Except, correct me if this is wrong, but he wasn't even convicted of money laundering, let alone the underlying crimes you suggest he was launder the proceeds of. It was simply for failing to register / setup an appropriate AML system. Whether any ML occurred, by whom, and in relation to what... are outstanding questions. If he had done all that and all they got him on was a 4-month technicality, that tends to suggest he was probably innocent (or the investigation was inept).
I'm not sure you understand the point. It isn't that CZ himself was specifically putting forth the effort to launder money. It isn't that he was specifically doing things to try and make it easier. The point is that he had a legal duty to actively attempt to prevent money laundering. Binance was legally required to do this to operate in the US, and did not. The court case produced messages from the Chief Compliance Officer pointing out a myriad of ways in which they were not complying with various laws of this nature and they were ignored.
The BSA is not a technicality and trying to reframe it as one is wild. It is to make sure that people that have a financial incentive to turn a blind eye to money laundering don't turn a blind eye to it. You don't need to be directly involved in the money laundering to be incentivized to let it happen.
The guy was punished with a 4-month jail sentence. It's reasonable to assume his crime was of the sort that would result in a 3-6 month sentence... generally misdemeanors.
It's certainly in a different category than speeding or jaywalking, but it's a lot closer to that than to the 150 years that Bernie Madoff got.