Whether we are living in a computer simulation is indeed a fascinating question, and I'm not dismissing it, but there's no proof or experimental evidence for it as far as I know.
I know about the simulation argument[3], but that's not a mathematical/physical proof or an experimental result. Lots of brainteasers and paradoxes have arguments structured like the simulation argument; one example is Olbers' paradox: Why is the night sky dark if there is an infinity of stars, covering every part of the celestial sphere? The argument about the stars seems to make sense but it doesn't count as proof or experimental result, and we know it's not true.
So I'm wondering how and why so many people are now convinced that we are living in a simulation?
[1] https://neal.fun/lets-settle-this/
[2] https://news.ycombinator.com/item?id=29866981
[3] https://simulation-argument.com/simulation
Two explanations that I think are unlikely:
First, I don’t think it has anything to do with software piracy since iOS or iPhone OS have always been included for free with the phone. So this is not the same situation as Windows Activation where Microsoft is trying to make sure you paid for the software.
Second, I don’t think it’s related to the carrier or cellular provider because you can (at least currently) activate an iPhone without any carrier or even a SIM card so long as you have an Internet connection (through wifi or USB). Besides, if this were about registering a carrier, the iPhone should connect to the carrier’s servers rather than to Apple’s.