what is gone, exactly?

By adding support for alternate stores, the monopoly argument is gone: everyone can build their own store now. Meaning, everyone with a store can kick out anyone else, and tell them to just build their own.

comply with their own ToS

…which they can change at any moment, but don’t really need to; most ToS include clauses about refusing service without having to explain why. If you ever agree to a ToS, better make sure they’re even supposed to notify you if they ever decide to cut you off.