Right? Not only can you download from any place on the web and install directly, there are also established third party shops like from Samsung and Amazon or even better, F-droid for Open Source stuff.
Maybe its classified as controlling the market, because most people don't know about alternatives and therefore Google is a monopoly. Even if there are alternatives, Google is currently in a position to control almost all Android smartphones. Similar to why Windows was classified as a monopoly, even though we had Linux for ages as an alternative operating system. So this paragraph is just a guess by me.