use F-Droid and convince friends and family to use it as well. The Playstore is a maleware distribution channel with abusive corporate rent extraction.

This right here, always.

Although I steer clear of the Play Store, I'm sure developers want their apps to be visible on it because of the massive display window it is. Although Quicksy, Conversation and, indeed, XMPP as a whole never got a lot of mainstream traction, getting booted off Google's platform won't help them any.

I would really love something like these abrupt removals to cause more people to abandon the Play Store in favour of F-droid (and other compatible repos, natch). That would require an entity with a much larger user base than XMPP apps switching to F-droid exclusively, though.