Font drawing is very much out of scope for a 3D API, that's something you (or a library) would implement on top of WebGPU. Likewise for line drawing, the API may expose some simple line primitives that the hardware supports natively, but if you want anything fancier then you're expected to do it yourself with shaders which is already possible in WebGPU.

The 3D API is just meant to be a minimal portable abstraction over common low-level hardware features, composing those features into higher level constructs is intentionally left as an exercise for the user.