Btw, crypto (like bitcoin) is only an alternative because of convention.
The complete history of bitcoins is globally trackable, and people could all decide that they'll pay more for bitcoins that came from Satoshi's initial hoard, or that they'll refuse to accept bitcoins that were ever seized by the FBI.
(Yes, there are mixers. But you'd just refuse to accept any bitcoin that took part in the mixer transaction, if any FBI coins were in there.)
I'd like to introduce you to Monero, which isn't globally trackable and also properly fungible so you can't refuse mixed transactions (since all transactions are protected).
Apparently it powered online drug marketplaces before Bitcoin existed.
Try doing that with crypto. Who are you going to arrest?
Every on- and off-ramp provider. EU legislation has basically created a database of real person to wallet mappings (for some subset of wallets). You can't take money from a wallet if you don't know who it belongs to (if you're an exchange anyways). The checks are a bit soft (ie. self attestation and stuff), but the public ledger part of crypto makes tracking far-far easier than with traditional banks.
The end game for this is that people in the West (and whoever they can pressure) won't be able to buy crypto to buy drugs or sell it when selling drugs, making it useless on a big scale.
This is essentially the purpose of localmonero and similar offerings. Trading cash for Monero in a p2p manner is going to be extraordinarily difficult to halt.
Why do you believe it would suddenly make peer2peer cash to cryptocurrency exchanges unviable?
And if you meant tracing the Monero itself, I suggest you read up on how Monero works—and how it differs from BTC—first.