The only difference in this is who you trust. Be it Apple, the community or someone you pay, you're still trusting that someone else's interests align with yours and they did things correctly.
In other words, this is not a technical problem. It's a problem that needs to be solved through regulation, because 99% of the people can't verify by themselves that their devices are actually private and secure.
Not really. There is a huge difference between trusting a single for-profit entity (who provides backdoor to iCloud in China) or huge number of independent people (each would like to get famous/rich for finding bugs).
But the kernel is only a tiny fraction of the system. There simply is no Linux system that even attempts to solve the problems Apple solves. There could be, but there isn’t - this is what we mean by the term ‘wishful thinking’.
You are speaking as if you know the opposite. Any links?
Plus the hardware is nice and actually works.
I agree with what you say in principle but here I am using an iPhone to type this while it’s been nearly 2 years since I ordered my Librem 5.
Making decent mobile devices that are more secure than an iPhone is not an easy thing.
Secure against entities they don't like. But intentionally insecure against entities they do like.