"development of chrome on desktop Linux have any benefits for mobile Linux?"
Android is the big market, that gets prime support.
Otherwise android and linux desktop just share the kernel (and not even the same one).
So the developement of chrome on android probably makes it a bit easier to target linux desktop, but not much.
(I still don't have WebGPU on my linux desktop but since quite a while on my old android phone)
"development of chrome on desktop Linux have any benefits for mobile Linux?"
Android is the big market, that gets prime support.
Otherwise android and linux desktop just share the kernel (and not even the same one).
So the developement of chrome on android probably makes it a bit easier to target linux desktop, but not much.
(I still don't have WebGPU on my linux desktop but since quite a while on my old android phone)