Streaming apps are a huge threat to Apple's current business model. Arguably, the gate to the kingdom had already been thrown wide open years ago with all of the capability that currently exists in the web browsers. It's mostly just a matter of engineering at this point to get around the censors and gatekeepers.
There is probably nothing Apple could do to prevent some determined engineer from building a streaming application framework that targets web instead of native apps for delivery of final server-side rasterized content. Best they could do is start blocking websites by IP/DNS which is arguably immediate grounds for Apple being split up and scattered to the seven winds by the FTC.
Hypothetically, you could develop this framework and build your own app store at myappstore.com. Instead of downloading binary images of applications from this site, it would actually host the application directly as a streaming web experience. For instance, accessing myappstore.com/MySocialMediaApp would be the resource that loads a full-screen server-side-rendered view of that specific application. All clients would just need to store a 256 bit cookie that is used for identifying the session. Everything else could live on the server, including 100% of the client view state. This model also makes it trivial to share application state between users or devices.
This kind of approach should sound like a massive boon to Apple in terms of them having absolute control & visibility, but I think they are just playing the current development ecosystem right now.