As a cross-platform graphics developer who is currently knee-deep in papering over platform incompatibilities, what I mostly care about at this point is compatibility. I don't care about shader size or compilation time, as long as both are reasonable. I do care about having yet another shading language to cross-compile to.
Please, everyone, just use something that already exists. It is frustrating how the big players constantly use new and incompatible graphics APIs to try to obtain some sort of competitive advantage, adding to the workload we developers have to deal with. There is almost no cost to the platform developers to add new APIs; instead, the costs are borne by the application developers. It's a classic case of negative externalities.
I miss the years where inspite of all its flaws, OpenGL was a non deprecated option on all the platforms. I know it left performance on the table, I know the drivers for some vendors were iffy and I know reasoning about performance across different vendors / drivers / platforms was difficult - but it worked most of the time and allowed me to have a mostly unified codebase everywhere.
ANGLE is the base of the WebGL implementation in Chrome. For WebGPU, we (Google) are working on a new native library called Dawn[2] that will fill the same role that ANGLE does for WebGL. I'm personally hopeful that Dawn itself can eventually be useful as a cross platform graphics abstraction for native apps as well as web apps. There's also Mozilla's gfx-rs[3] in the same space.
[1] https://github.com/google/angle