Consider the whole history of OpenGL, Metal, Vulcan, WebGL, WebGPU...

It would have been a mistake to keep using OpenGL, and WebGL was perhaps a mistake from the beginning. It was the wrong abstractions. Metal and Vulcan are clearly better abstractions for GPU APIs, and it really doesn't matter too much that Metal is Apple-only because they're close enough that you can have a good Vulcan API on top of Metal (MoltenVK). That is, what matters is that we converge on the same abstractions, and those take a long time to get right.

Now in the end we've gotten WebGPU (which isn't only for web browsers btw, can be used from native apps too) that can provide a nice universal cross-platform API.