Companies like Signal are founded on privacy and encryption, but with Apple, privacy is a nice-to-have, limited to its other business objectives (like how Apple is "committed" to reducing waste to the extent it can sell dongles, chargers, and earbuds separately, but not in terms of repairability). You can count on Apple to value the appearance of privacy, and in protecting information from third parties without user consent, but not so much being private from Apple itself.
For example, here's an article on Apple and privacy from a couple months ago https://www.politico.eu/article/apple-privacy-problem/ .