It's actually a bit more subtle than consumers not buying them.

When LTE came out, it was inefficient and used lower frequencies than cell phones used before. So they needed big phones that they could stick big batteries and antennas in.

Smaller phones existed, but often lacked features of big phones, and battery life was terrible due to the aforementioned power consumption problem. Likewise, reception suffered.

Now, the power problem has been solved and LTE uses less power than CDMA techs did. Antenna and radio design has improved to mitigate reception issues so smaller antennae don't hurt as much as they once did. However, now phones have giant camera modules in them and antennae for a plethora of services and features they think people want like UWB, NFC, wireless charging. (They all have their place, just stating this because they aren't "essential".)

People stopped buying small phones because they were "terrible" by comparison. Then manufacturers claimed people didn't want small phones, so they stopped making them. Now we are stuck because all the junk they throw in phones need all that space.

Tl;dr: the wireless industry killed small phones and blamed consumers.

I have not forgotten. And this is not so much swimming upstream but rather, as Captain America said, it's more like planting yourself like a tree and say "no, you move".

Yeah, this seems like a targeted ad written by some llm. I have a larger phone and still cannot stand the size of the "keyboard" on it.. Can only imagine how fun it would be typing on that screen, even if the keyboard was fullscreen.

More so they upsold people to the bigger models. If they had exactly the same specifications other than size, I bet a much larger set of people buy the smaller one. The phone in this post does look a bit too small though.

Nah, OEMs had to make them larger to provide sufficient cooling surface area for the battery and cpu.

That was the first driver, and then marketing took over to make larger phones seem like a better choice.

Now that Android is much more power efficient (and the hardware is too), we could have smaller phones with only a modest reduction in performance.

Stuff like ceramic or glass backs were also as much about cooling, but marketed as a cool feature.

Ceramic and glass transfer heat far better than plastic. So when you're running your flagship phablet at max to play a game, it can shed that heat much more readily, and also charge the battery at 15watts.