Typically, devs will first push their releases to github so they're available via direct download and Obtainium, and then push out to whatever stores they use for mainstream distro. It keeps everyone happy!
Ah; im very new to AppStore distribution; I was just pushing the apk to my blossom server and to zapstore’s
Another benefit is that the github repo makes it easy for users to go back in time and grab previous releases, which is good if they're debugging a problem and want to see if some change happened between releases that is causing their issue. Unless I'm mistaken, Zap Store doesn't offer historical releases.