Privacy is a thing that people legitimately desire as well. You don’t tell your neighbors about the valuables in your home. If I acquire BTC to hold long term, it’s in my interest from an opsec perspective to keep it secret, keep it safe.

Password managers and E2E comms apps as well. If I were running a government surveillance program it's a total no-brainer that one of the things I would do is develop and publish world-class versions of both of these, though obviously concealing the fact that they were connected to government surveillance from the users, and probably most of the developers as well.

Tornado is open source. You can go check if its a honeypot if you're worried.

Maybe. Most popular mixers are now open source, wasabi, samourai, tornado.cash