> also I don't see why target WebGL 1.0 in the days of WebGPU, WebGL 2.0 yes, because WebGPU isn't yet widely available.

Because not every hardware capable of running PS2 level games supports the newer APIs.

> Also OpenGL 3.3 is from 2010, whereas OpenGL 2.1 was designed for 2006 hardware, how back you want to get?

Doesn't matter how old it is, what matters is if it has the required features or not. For the use case being discussed, GL 2.1 is sufficient so there's no good reason to not target it. That's my philosophy at least. When I write code, I always use the oldest library or API that has the stuff I need. I don't just go automatically for the latest one.

No webgl, SDL2/3 + OpenGL 2.1 can be enough to run most PSP games well if some of the FX's are reduced down or replaced.