If WebGPU really does perform better in an apples-to-apples comparison (i.e. running the same shader) then there's something seriously wrong with Apples WebGL implementation.

edit: here's that example translated verbatim to WebGL if you want to compare: https://www.shadertoy.com/view/Mt2fRy

So the exact equivalent in WebGL is noticeably harder on the system than the WebGPU version.

Most of the WebGL demos that get posted around here, always have issues running on my mid-range devices, that don't have any issues playing my collection of 3D games.

So I still look forward to a 3D Web API that can actually compete with native 3D across all mobile devices, not only on flagship ones.

Or proper implementations of WebGL, if that is actually the issue.

https://news.ycombinator.com/item?id=16086537

I suspect that Three.js is the main reason why so many WebGL demos are slow, rather than WebGL itself.

Might be, but what counts is the perception when someone goes to a given web page.

EDIT: Just tried your shader toy example on an LG Power X, with a Mali T720, it averages on 20FPS.