But, here is my thinking. Android is operated the way it is because it cements Googles dominance with its other services. Maps, Chrome, ..etc always ship with the certified Android phones. Google proper doesn’t pay anything for that privledge currently.
If broken up that first class “ships with the phone” stuff is now up for grabs and seems like it would be a valuable revenue stream. Also there is usage data which can be monetized. Play store revenue would still be there as well.
Custom spins of the OS for specific industry use cases with professional support might be attractive to a smaller company which just had Android whereas it isn’t lucrative enough for Google as a whole. Also these custom flavors might not ship with Google services so there is a natural disincentive to explore this.
Android on its own would likely monetize very differently than it currently is as part of the Google mothership. It would need to have a diverse set of partners. Even if it was just as a regional service reseller where it is taking a cut of service revenue in exchange for first class support on the OS.
I can’t help but think that this realigning of incentives would be beneficial for the market as a whole.