Maybe I'm misunderstanding something, but Bitcoin doesn't HAVE an anonymity set except in the most trivial sense of the word. Your BTC can be followed, forever, with automated tools. If it hits a KYC exchange, somebody is due a visit if it pleaseth The Man to do so.

While #monero, after it changes hands a few times, the list of possible suspects is far too long to investigate, much less visit, since most of them will be too small-time to be profitable to rob for the manpower and noise it will create.