The encryption key management is performed in a hardware sandbox. iOS and apps running on the phone cannot access it.
I think that's the gist of it anyway. I'm too frugal for an iPhone so I haven't read up on it in detail.
I'm not sure why only Apple and Sony make decent, smaller phones.
So you pay your money for an iPhone and get Pegasus malware anyway ... or get a far cheaper device and use reasonable, sensible, security practices (no 3rd party, don't view unexpected payloads, etc.) and get a similar level of probability of infection.
I take it you don't browse the web or use apps at all?
Though granted the underlying OS might be more vulnerable once FF had been exploited. The homogeneity of Apple surely makes a greater target though, which I'd expect to balance it out.
Presumably you and the GP have done prior to the frugality claim - like people who don't just install any old shit get exploited in a financially more costly way on Android.
However: It’s dated now, almost two years, so keep an eye out for a potential successor. If they don’t release a successor, then they played their cards very well and roped tons of us into their system with a too-good-to-be-true model. There’s probably a name for this play in economy text books :p