Google Play is accessible only if you hook your Android device to a Google account AND you Andorid device vendor has put up the $$ to use the proprietary Google

Google Play is accessible only if you hook your Android device to a Google account AND you Andorid device vendor has put up the $$ to use the proprietary Google apps like Play. The real question is why so many apps are distributed only through Play, excluding privacy-conscious users and open source Android devices.