"Useless without access to Android app stores"
You can find an open-source, non-Google infected version of pretty much everything you'll ever need that runs on Android which is itself an open-source program. And if you can't find a particular app to exactly suit your needs, go ahead and make it yourself.
And since Android is open-source you can find plenty of disinfected versions of it at places like this:
Xda-developers.com
The most difficult part of freeing yourself from Google's grip is unlocking your phone so that you can load a new version of Android onto it. But there's an easy fix to that problem - just don't buy a phone that locks you into the manufacturer's pre-loaded operating system. One of the reasons Huawei is getting all the bad press right now is because they
don't lock you into their pre-loaded op-sys and
that makes them a threat to the big tech companies with their pre-installed govt surveillance software.