@avatar1024 Look into who funded it, who governed it and steered it in the first couple of years of its development (that is - if you can even find that information these days - seems like someone did a good job of scrubbing). After that entity got involved, all of a sudden, Signal was pushed by everything out there, including your microwave, as a "privacy messaging app".
I'm very privacy focused (some may say paranoid) because I, unlike many, don't take the rights for granted and I've looked into Signal a long while ago (short after it started appearing everywhere) - found multiple very privacy oriented and trustworthy sources disclosing a lot of early details on Signal and its connection to specific entities. Never looked into it after that - might as well use WhatsApp and Telegram (which is a killer app) knowing well that they aren't privacy oriented.