I'll quote Tim Minchin here

"If you wanna watch telly, you should watch Scooby Doo
That show was so cool
Because every time there was a church with a ghoul
Or a ghost in a school
They looked beneath the mask and what was inside?
The fucking janitor or the dude who ran the waterslide
Because throughout history
Every mystery
Ever solved has turned out to be
Not magic"

Germ Theory

Diseases used to be associated with paranormal powers or the wrath of gods in most cultures. The discovery of microorganisms and advancement of medicine may be our civilization's greatest achievement.

Science deals with the natural, gods are by definition supernatural.

Science can not either prove or disprove existence of supernatural. It may only erode the reasoning why supernatural should exist.

That reasoning is subjective, and as such, there are no definite answers to your question unless we add additional constraints.

Evolutionary biology was the main one

Heliocentric model.

Cosmic distance and time. Light speed as a limit.

The geological age of the Earth.

Dinosaurs.

Evolutionary theory.

Continental drift.

The periodic table of the elements.

Quantum theory, including wave-particle duality.

The Heisenberg uncertainty principle.

Black holes.

Religion is deliberately non-falsifiable. No matter what scientific proof you can come up with, at the end of the day they just say God is fucking with us burying skeletons of creatures that never existed and such.

The fact that it needs to be constructed that way is frankly all the proof I need to toss religion in the garbage, but everyone isn't so cavalier about the disposition of their "immortal soul."

Honestly immortality and the very nature of God are both abhorrent to me. If religion were true, the best I could hope for is to be cast into a lake of fire and be destroyed, so I kinda win either way. Worst case is all religion is wrong but so is atheism and I have to spend eternity with an entity who is less of a malicious cunt than the Abrahamic god.

Letter from Charles Darwin to Asa Gray (22nd May 1860)

With respect to the theological view of the question; this is always painful to me.— I am bewildered.— I had no intention to write atheistically. But I own that I cannot see, as plainly as others do, & as I shd wish to do, evidence of design & beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars, or that a cat should play with mice.

Source

The scientific method itself considers any as yet unsubstantiated theory as hypothesis. Applying this to the idea of God would leave one agnostic on the issue.

A couple of prominent examples of religious dogmas disproved by scientific discoveries are the Copernican Revolution and evolution by means of natural selection.

God's an unfalsifiable claim, so there really isn't anything that could test that hypothesis.

Pretty much any scientific test/discovery that counters anything in a religious text whose adherents view the text as completely truthful and literal. But sciencey stuff might not have much of an effect on religious folks who view their texts less literally.

But anyways... heliocentrism, germ theory, gravity, evolution through natural selection, probably a huge chunk of the field of archeology, plate tectonics, radiometric dating, probably the written language at various points in human history (but that's not really a discovery), trans species organ transplants, decoding DNA, direct genetic engineering, CRISPR, radio telescopy.

Translative spoken word by the time a second hand account of the word of god becomes the word of the person speaking. Weird god never came back once we had verbatim recording techniques to address these inaccuracies.

It wasn't any particular scientific discovery that weakened religion. It was the popularity of science fiction that did it. As Arthur C. Clarke put it, "Any sufficiently advanced technology is indistinguishable from magic." People can now imagine how miracles are done without invoking anything supernatural. We might not have the tech to do it yet, but we have a pretty good idea of potential methods. That has placed a lot of "creator god" religions under pressure. Create life? Tech will eventually do it. Create a world? Sure, tech again. Given enough tech, a solar system can be spawned. Water into wine? We're halfway there with Kool-Aid. We already have vimanas (those ancient Hindu flying vehicles). We call them airplanes or helicopters. We can destroy a whole city with a single weapon. So why should we worship a supreme being who supposedly did those things?

Assuming we can conquer poverty, religions that survive will be centered around improving the human condition. Worshipping dieties will eventually fall by the wayside. It will still be a long process. You can't dispel faith with reason and facts. And people in poverty tend to embrace religion because it gives them comfort and hope that things will be better in the afterlife.

You need to define God first.

Printing presses, industrialized education, and the industrial revolution.

Giving people en mass the time study and educate themselves.

Sanitation.

Doesn't even take science to debunk religions, yet you can't prove the non existance of a god

Science and religion are often compatible, I know of some Hindu thinkers (for example) who say scientific knowledge is to be taken as truth and religious truth should not contradict it - just that this scientific knowledge cannot explain the whole mysteries of the cosmos. You might be aware of "the god of the gaps" and arguments like that, or that God somehow created the universe using the laws of physics as we understand them. Historically, scientific thought and religious thought were often united and people pursued science and philosophy due to attempting to understand God (like many Islamic scholars in the 7th century or like Renee Descartes who ultimately sought to prove the existence of God by pure reasoning). Science as a complete system of belief without some religious aspect is actually a fairly recent phenomenon that likely had very little to do with any particular scientific discovery.

Indeed, science can do very little to explain why things happen. It's great at explaining how - e.g. science is great at explaining how fire burns or how a calculator can display an answer but it can be iffy on why. Now, "why" fire burns is probably more of a malformed question like what's north of the north pole but we're human, we like to ask why and seek purpose. Meaning makers.

The decline of religiosity wasn't really driven by science showing biblical stories weren't real, it's a process driven by material reality and class relations. Although many people considered themselves Christian or religious in the west, they were very Deist and didn't think God had much influence with the world apart from answering paradoxes like what was the primum movens etc.

Going further back, religion wasn't a choice or something to reason to - it was just your life and your community. In medieval Europe, you didn't really reason your way into a system of beliefs they all tied together into an economic system called the feudal mode of production. You just were a Christian and so was everyone you knew. Maybe some monks debated some esoteric aspects of theology but most people just lived their lives. This lasted for a while through to the Enlightenment and the emergence of capitalism in the 17th century. Except for some malcontents and rebels, people still didn't reason towards being Christian, say. It was just your life - more like a hangover from that older mode of production and social cohesion than something necessary to maintaining capitalism.

Fast forward to the actual decline of religiosity and rise of spiritual none-of-the-aboves and nothing-in-particular. This was a process started in the mid 20th century (not really in WW1 which was conceived often as a holy or religious war by the soldiers and officer class including miracles and appearances of angels and so on). In reaction to the rise of consumerism and individualism - now religion became a choice or affectation! This is where we start to see the irreligious begin their massive growth but especially by the beginning of the 00s. It's tempting to say Quantum Mechanics, GR, a scientific basis for cosmological origins like the big bang are responsible for the loss of religion - but in my view, these just coincided due to a third cause (that of economic changes and the settling in of mature capitalism).

The most reliable way to lose faith isn't through science, it's reading their holy text.

In general, nothing about science ever shakes a theist's faith, and I doubt it ever will. Reason being: the moment science breaks new ground, religion retreats further back into the unknown. As long as there is an unknown, theists will have something to take shelter from.