It's quite useful for things like skia or piet-gpu/vello or the general category of "things that use the GPU that aren't games" (image/video editors, effects pipelines, compute, etc etc etc)
Those already have their own abstraction API, and implementing a RHI isn't a big issue as FOSS circles make it to be.
I suppose that's true, yeah. I was focusing too much on games specifically.
would it also apply to stuff like the Switch, and relatively high-end "mobile" gaming in general? (I'm not sure what those chips actually look like tho)
there are also some arm laptops that just run Qualcomm chips, the same as some phones (tablets with a keyboard, basically, but a bit more "PC"-like due to running Windows).
AFAICT the fusion seems likely to be an accurate prediction.