I think one solution to this problem is the global regulation that gives governments control over the data of all addresses and transactions, but this action doesn't look recommended for most of the Bitcoin community, because it hurts the privacy and anonymity that gives Bitcoin and other crypto currencies the advantage. If Bitcoin was regulated globally, it would look like any other payment system throughout the world. Indeed, some exchanges like Coinbase and Binance are forced to share their data with the American government. This facilitated the seizing of stolen money in some cases.
Another solution, the biggest players in crypto collaborate and organize a protocol that gets rid of illegal activities, and at the same time protects the privacy of users. However, we can't imagine a full disappearance of illegal activities in which crypto is used as a means of payment, because the thieves or scammers can move to using technologies like Monero or Zcash.