> The fun fact is that those people have 100+ apps on their phones, which run in the background, draining their batteries, tracking the sh*t out of them,
This is wildly untrue on iOS. Perhaps people have 100+ apps. But the rest, not so much.
> Are they silently shut down/paused after a while?
Yes. This has been the case since 2008 when the first version of iOS supporting third-party apps was released. Background refresh allows some quanta of work do be done when an app is not in the foreground, but only limited things.
This is wildly untrue on iOS. Perhaps people have 100+ apps. But the rest, not so much.