Well if you're steering the argument on to other platforms then I'd use the PC gaming market as the model. 1 dominant app vendor (Valve) however there are multiple competing vendors (GOG, Amazon, Epic etc) some of which are aggressively pursuing market share.
For the most part all done on a Microsoft OS, a platform that Valve, Epic etc have paid nothing to develop.
It's a model that's working and doesn't seem have done Microsofts 950bn$ market cap any harm at all, consumers happy to have price competition and to date I've yet to encounter a single example of deliberate malware distribution through any of the market places.