I’ve got a cousin that does exactly that, and it’s like everyone already said; maintaining multiple “stores” takes more time than it’s worth usually.
Now, he did say that some apps are better off not being on the play store because the use case is for people that are more FOSS oriented, and/or do things that Google doesn’t like (like anything that fucks with ads as an example). But his stuff is like a lot of the open source on the play store; he does it because he’s willing to share things he makes for himself, but isn’t willing to jump through multiple hoops to share it.
And, open source or not, if someone wants to get paid for their apps, there’s only two realistic places to publish them; play store and amazon store. The amazon route is a joke for any developer I’ve ever talked to.
Oh, as an aside, I did ask my cousin if he’d just send me the APKs for the ones he’s done. His response? Git gud nub. Told me to compile or die lol.