More immediately, push as hard as possible against it. No mountain is too big that it can't be moved with the right strategy.

On the longer term, forking AOSP would be a good bet, I think, but do note it requires a continuous effort/investment. In the same vein, pushing for Linux and non-Apple-developed BSD systems for mobile (the latter dunno if exists, but if Apple did it, others could also).

Another thing, but for much longer down the line, to change culture. For example, to stop using, as the saying goes, "the language of the enemy", like instead of "sideloading", which implies avoiding the main/correct way, say "installing", and "program" instead of "app"/"application", same as more standard computers. Also if the situation allows, whenever possible, to point the problem Google is, and to not cause apathy, to include solutions in the argument.