Yes that's true but it's weird they only focus on crypto investors' families? There are many rich people in France, what's the deal with cryptobros?
Crypto is advertised as providing irreversible transfers, and having ownership of assets solely established by ownership of keys. It shouldn't be surprising that such features would attract criminals.
You can easily establish the connection from a bank account to a person. A connection from a crypto wallet to a person is extremely difficult. Money laundering with crypto is also much easier (and cheaper usually).
In the vast majority of cases, it's actually extremely easy. It took less than an afternoon for me to learn how to trace 90%+ of transactions on either BTC or any of the networks built on Ethereum or an Ethereum-like protocol. There are large companies that specialize in exactly this, which make tools that allow government agents who have no particular crypto expertise to trace the majority of transactions.
It is possible to make your transactions extremely difficult to trace, but you really, really, REALLY have to know what you're doing.
Law enforcement loves that people think it's easy and cheap to launder money with crypto, though. It's made it vastly easier for them to catch those people!
I never doubted that it's possible but it's way harder than identifying bank accounts. There is a massive business behind crypto tracking, that's why companies like MasterCard have acquired CipherTrace. Some years ago there was a really good article / case study from them. I think it was related to a ransomware gang and they were able to identify the threat actor's wallets through crypto tumblers and chain hopping. It's just a matter of how much money and time are you willing to invest into finding out and not a matter of possibility.
You can trace the BTC or Ethereal transaction of coins, but you cannot trace the criminals after it's converted to Monero or some other "privacy" chain on an exchange run on the dark web. After that you're just tracing other owners, possibly who have no idea where that it was stolen. It literally takes a few hours to wash it all out.
It’s harder but not totally impossible with the traditional banking system. https://en.m.wikipedia.org/wiki/Bangladesh_Bank_robbery
Guessing their profits are regularly illegal or untaxed, so they're less likely to involve the police.
Seems unlikely given who has been targeted. I doubt the Ledger or Paymium guys have been evading tax on crypto given that they're publicly involved in it and likely would be scrutinised more than the average person by tax authorities.