Binance was up for “money laundering and tax offenses” issues because they deal with large sums of fiat money independent from what’s being sold. Replace Bitcoin with physical artwork and you can still run into issues here.

Coinbase similarly ran into issues not because they were selling crypto but from related activities which fall under SEC regulations. It’s one thing to operate an auction selling pigs or crypto, but when you start getting into ‘related activities’ they don’t necessarily fall under the same umbrella. Read up on “Pork Bellies” and you might start to understand the issues.