I don't see what your point here is. Apple forces developers to do something. Google does not.
Information on alternative Android app stores is trivial to come across. They're just not very popular or worthwhile because Google isn't a crazed overbearing dictatorship like Apple. You can go implement whatever payment/notification/clone-of-stock-app/browser app you want and no one will stop you. IIRC, you don't even need to pay Google a yearly fee to be a developer, unlike Apple's greedy rent seeking.
Information on alternative Android app stores is trivial to come across. They're just not very popular or worthwhile because Google isn't a crazed overbearing dictatorship like Apple. You can go implement whatever payment/notification/clone-of-stock-app/browser app you want and no one will stop you. IIRC, you don't even need to pay Google a yearly fee to be a developer, unlike Apple's greedy rent seeking.