If Apple lets consumers begin installing apps onto iPhones from sources other than Apple itself, could we see dozens of app stores bloom, from companies big and small, as some advocates of greater competition in the mobile market predict?

Not likely. The odds of success are stacked against such alternatives, although a variety of companies are still likely to give it a go. One could be Microsoft: As early as 2016, the CEO of the software giant, Satya Nadella and other executives at the company discussed plans to release a mobile version of the Microsoft Store—currently a marketplace for software on PCs—as an app for Apple’s iOS, say two former Microsoft employees with knowledge of the matter. Microsoft’s discussions have focused on the possibility that regulators might force Apple to allow independent app stores on its devices, the employees said, something that is now reportedly happening.

Last week, Bloomberg reported that Apple is preparing to allow the installation of apps from third-party app stores and directly from developers in response to a new European competition law that goes into effect in 2024. There are still many unanswered questions about just how much freedom Apple’s changes will give developers to sidestep its official App Store—and the 30% cut it currently takes of app revenues. And on Google’s Android, a mobile platform that has for years permitted alternatives to its Google Play store, there isn’t much evidence that consumers will use app store offerings from third parties.