WebGL 2 has a lot of stuff which is very nice if you are writing WebGL code, and some things that were just impossible in WebGL 1 even with extensions: https://webgl2fundamentals.org/webgl/lessons/webgl2-whats-ne...

There is very little reason to restrict yourself to WebGL 1 anymore, but many existing projects are still on WebGL 1 because Safari didn't support WebGL 2 when they were written.

WebGL 2 is going to be the best option for a long time. While WebGPU is in progress it will be many, many years before it is supported anywhere near as widely as WebGL 2.