Unnecessarily rude but okay.

>Two years ago google lost an antitrust case brought by epic games about their android store practices:

It's wild this ever happened when their competitor literally doesn't allow third party apps installed in any way.

>supply side (sites with space the sell for ads) and demand side (market of advertisers bidding on that space) so it can play both sides - and (crucially!) it has integrated them so as to lock in both advertisers and publishers.

You could argue every grocery store does this, they provide the 'supply side' (shelving), brands negotiate for both shelf space and shelf positioning. There's not a super obvious bidding market like Google setup, though ironically Google's method actually makes it easier for smaller companies to participate. Getting a small item in a major grocery store chain is a major move that many companies simply can't do.