That said, of course developers built the market, but not every developer built the market. Apple developers built it. Other developers have chosen to sell inside of it.
Without Apple Developers creating the store itself those developers couldn't sell anything. Apple could 100% do that if they wanted. In fact, the first iPhone was as such.
Not to clients like myself who bought it because of the security provided by that locked-down environment. I'm not concerned about a game not being sold on it. It provides for a host of other purposes.
If executed properly, those two seemingly opposed features could be achieved and make more people happy.
Make it possible to unlock iOS ability to sideload apps, either through a unique code, a security certificate, or a simple toggle and allows businesses to lock down (but not remotely enable) this ability using their MDM.
Of course, put the usual disclaimer that enabling this feature could weaken the device security, and don't simply enable it because an app or a website told you so.