I mean, I've known a few developers that worked at apple. I trust them every bit as much as the average developer who reads open source code. They vouched that

I mean, I've known a few developers that worked at apple. I trust them every bit as much as the average developer who reads open source code. They vouched that the code they worked with at apple was attempting to be secure and wasn't trying to steal user's data. If I'm not going to read the source code myself either way, why should I trust that random open source code-reader X who says "yup, didn't see any malicious code" vs a developer friend who works for apple and says "yup, no malicious code"? Honestly, more often than not there's a lot of overlap between those people... And I'd bet that there's a ton of eyes I'd trust on iOS's source code given how many devs apple pays to work on it, while I think there's far fewer on most non-corporate open source projects.