The part about your phone identifying sexts and ratting you out to your parents is kind of gross and inserts itself into privacy issues within families that I don’t think it is wise to let machines do.
But to be clear, that is predicated on your icloud account being linked to your parents’ account, in which case your parents could always read your messages (and everything else) at will, because it’s basically their account, and they have all the crypto materials. It is not a “backdoor”, and doesn’t involve changing anything in terms of the underlying security.
And it’s the same with scanning iCloud against child porn fingerprints: any unencrypted cloud storage was always going to be subject to that sort of thing, and some jurisdictions require it. Apple are trying to claim they’re doing it with stronger safeguards than other providers have, which may well be true, though I wouldn’t attach much importance to that.
The reason big tech invades your privacy is advertising, period. So when ad-funded media (which is to say, all media) implies that the biggest threat to your privacy is Apple, bear in mind that this is exactly like Skeletor warning you about He-Man’s ambitions to rule Eternia.
EFF is not funded by advertising, and they have plenty to say about Facebook, Google et al. too, but they know very well that even fair criticism of Apple will be amplified far more. Their beef with Apple is ideological (hey, He-Man’s dad is a hereditary tyrant after all), but IMO they overplay this to the point of being counter-productive. They seem too focused on Stallman-like purity tests to admit that one company can be better for your privacy than any other, even in principle.