Fair enough, I agree with most of the things you said. The one I got is made of aluminum and doesn't feel cheap/thin at all, I guess they have both cheap and "professional" options. Personally I wasn't looking for something really unique, just for something that had a decent performance for a laptop and works well with Linux. I searched around and this model ticked all my most important boxes.
I don't know whether Clevo engineers throught about Linux when they designed the device or not, but I can say after configuring it properly, it works without any flaws.
As for buying straight from China, I consider the idea, but at the time I didn't find a way to buy it for cheaper than buying from a reseller. I'm in Europe, perhaps in the US or in Asia it would be different.
I am not sure... in the case I'm referring to, they were lagging also when scrolling. But it was React, so native browser rendering. And they were actually very large tables, so we had to do some funny things like viewport culling (see react-window).
For what it's worth I've never had any similar performance issues with tables in Flutter (web with the canvas-based render engine, not Android) when applying the same culling technique, they just ran fine at any resolution. Different hardware, though, so it's not an apple to apple comparison.
In any case just to be safe I would personally assume less pixels = less work = less power = more battery life. My opinion is very unscientific though.