The problem is security, as usual. You can use opengl to exploit a host system, therefore all interactions have to be whitelisted and checked. Compute shaders I know can be crafted to bring your PC to a grinding halt.
Webgpu will be a lovely security nightmare. The underlying hardware is inherently insecure. It's fast, not safe. Safety is simply not a feature of graphics operations.
Yep. Browsers could protect against this much better by profiling the fragment shaders instructions, size of data buffers, and requiring the render loop to have a delay. But then we get into managed GL territory and it's no longer really GLES, it's a library that gives you some features of GLES.
Webgpu will be a lovely security nightmare. The underlying hardware is inherently insecure. It's fast, not safe. Safety is simply not a feature of graphics operations.