Middleware engines already solved that problem for about 20 years now, no need for WebGPU outside the browser.

Not everyone wants to use existing engines. Or are you saying you want to embrace vendor lock-in in that regard?

Yes, definitly, that is the approach taken by AAA game studios.

A plugin framework for 3D APIs is probably the easiest part to implement on a game engine, specially when API like OpenGL and Vulkan already require implementing one due to extension spaghetti.