It's a nonissue when you look at the state of macOS attention to detail nowadays, regardless of which side of the fence you're on.
To begin with, yes. The decline only started around ten years ago.
So, it may makes things a little easier for some GUI scripting. I can also see the UX improving for some disabilities, but I know that is merely coincidental rather than intentional.
Same applies to spaces where there's also delay applied before it appears for whatever reason. It would be nice if this fixed (on non-touch Macs as well).
Touch affordances and UI does have to be visible, and there is only one screen. So the touch affordances and mouse affordances are mutually exclusive: targets get larger, padding expands, UI gets dumbed down, etc etc.
Of course, there's the extremely common case of keyboard support being half-assed or missing from GUI apps. But that's not mouse affordances making things worse, that's developers just not having the time or inclination to have great keyboard support.
Whereas, touch affordances seem like they'll be a lot more disruptive.