There are multiple big business offering blockchain analysis and transaction tracing/de-anonymizing services. Chainalysis, Elliptic, IdentityMind, CipherTrace, Crystal, Elementus, to name just a few. The majority of the work these companies do is not in illegal or cybercrime cases, though. The majority is for exchanges which like to spy on their customers and freeze your account if you are deemed to be doing something they don't like despite being perfectly legal, such as using a bitcoin casino or sportsbook. Some exchanges like Coinbase even have their own in-house blockchain analysis department in the form of Coinbase Analytics (rebranded from Neutrino).

Although KYC is obviously a massive no-go, if you are interested in privacy then you should not be touching centralized exchanges at all.