You'd think that the privacy-focused coins out there are most used in the deep/dark web. XMR, Dash, ZCash, BEAM, etc. are the ones that come to my mind, but I think people are changing those coins to BTC as fast as possible just due to the fact they are shitcoins.. Or they might be just using BTC in combination with mixing services.
If that's the case for privacy coins, what truly then is their usecases. If I were a layman, I will choose Monero and Dash to be the favorite dark Web coins over bitcoin