Funny how the exact same arguments get applied to Apple in the exact same markets. Weird how “no one has a choice but to use Google product” and at the same time “no one has a choice but to use Apple products.”
To reach Android users, you must go through the Play Store.
Realistically, these stores are not in competition. They have monopolies over their respective markets. If one store offers a better deal to developers, that doesn't meant the developers can all flock to that store and abandon the other one. Developers still must deal with both. As a result, the regular forces of competition aren't doing their job here. Neither store has any incentive to make their terms better because they won't gain any developers by doing so.