I don't really get your point. The accessibility story can surely be improved, but it's absolutely 100% better on Android, than what we have on GNU/Linux today, so at the end of the day it's just one more choice for end-users.
And keyboard and the like will also get a chance to get fixed if more people are interested in the platform.
I dunno that it will be improved. ChromeOS is pretty bad on that front (or at least was a couple years ago when I set up a chrome book for my elderly dad).
And keyboard and the like will also get a chance to get fixed if more people are interested in the platform.