

iOS does have an API for apps to record the screen throughout the OS these days through Broadcast Extensions, but it has to be user-initiated through the control center screen recording toggle (where they then get to pick what app to record the screen to instead of just saving as a video), it wouldn’t do that people think the T-Mobile app is doing
Instagram is extremely popular, and it’s heavily promoted inside of there, with Threads content embedded to almost look like Instagram content but when you tap on it it hops you over to Threads. I’m not surprised that they’ve been able to build a user base while X declines