To be fair, it's much easier than one can imagine (try ollama on macOS for example). In the end, Apple wrote a lot of longwinded text, but the summary is "you have to trust us."
I don't trust Apple - in fact, even the people we trust the most have told us soft lies here and there. Trust is a concept like an integral - you can only get to "almost" and almost is 0.
There are multiple threat models where you can't trust yourself.
Your future self definitely can't trust your past self. And vice versa. If your future self has a stroke tomorrow, did your past self remember to write a living will? And renew it regularly? Will your future self remember that password? What if the kid pukes on the carpet before your past self writes it down?
Your current self is not statistically reliable. Andrej Karpathy administered an imagenet challenge to himself, his brain as the machine: he got about 95%.
I don't trust Apple - in fact, even the people we trust the most have told us soft lies here and there. Trust is a concept like an integral - you can only get to "almost" and almost is 0.
So you can only trust yourself. Period.