A new study recently conducted in the European Union showed that bitcoin is used with an illegal target in just 0.67 percent of cases. That is, the whole problem with the illegal use of bitcoin is in fact far-fetched. For various illegal purposes, coins with a higher degree of anonymity are used, such as Monero, ZCash and others. Bitcoin is only relatively anonymous.
And this problem was far-fetched and contrived right from the start. Satoshi himself never considered Bitcoin anonymous and untraceable as he uses the term “anonymous” only in reference to public keys in his WP. In fact, the Bitcoin blockchain, the so-called "public ledger", is a perfect tool for forensic analysis. First Bitcoin users like those unbanked from Silk Road and other similar DarkWeb markets may have been too optimistic in this regard and got caught in the end when their transactions had been properly analyzed and scrutinized. And I don't think other coins are totally safe either
As only time will tell if they are truly secure and anonymous in practice