i think it's not productive to call it a literal/actual/effective monopoly, since it's designed to be monopoly. The problem is not so much that it's a monopoly but that it advertises itself to developers and to users as being an open more or less market, which it isn't since it's by design rigged and censored. There's a legal gap here probably because such situations are unprecedented (where a company builds a market…
How is being designed to be illegal a defense? If anything, that makes it worse.