Because for those states and companies, crypto is a toy and not real money. Also not having a bank means your transactions are always final (nobody is putting up with multisig).
Crypto has been great for buying drugs via darknet and taking money from investors for partnerships that don’t exist or make sense. Been using it myself actually. Also facilitates gambling, either via crypto casinos or directly against its price. Outside of that, traditional banking wins.
It’s also questionable whether a state could acquire so much crypto quietly at this point. Most big holders are either very publicly about it, like Argentina, or confiscated it from illegitimate sources (like when Germany raided a darknet market operator).