I conclude that our police simply do not have enough experts to follow up on something like this.
And that's why Chainalysis is trying to take over the space of forensic blockchain analysis. I have nothing against using their methods to catch criminals and whatnot, but it appears that some of their 'investigations' aren't really connected into some criminal activities. They literally peer into any transaction that they find interesting and connect all the dots, somehow lessening the anonymity of those people involved in the said transaction. Police intelligence divisions aren't really well versed in the said area just yet, but contracting Chainalysis and other blockchain analysis companies for forensic analyses of crimes involving cryptocurrencies isn't really good either.
But if you use a coin switching service that doesn't require KYC and you switch into Monero and from the provided address send it to another Monero address, it's over. There is no single way in the world to trace down transactions on the Monero blockchain, at least not from what we know to date.
If the criminal goes through Binance it might be easier, but still there will TOR and / or VPN involved. You just can't stop these coin switching services because they can be founded anywhere in the world. If you can't shut the website down, how are you going to stop it? Surely the risk is with the attacker that the person running the switching service steals the funds, but the attacker just goes step by step, doesn't send 4000 BTC. If they do it right, no way you catch them. That's why it's more effective to force people to prove where the money comes from if they ever cash out. I am not saying that is the solution to the problem, I am just saying that KYC won't stop (s)extortion at all.