I think that ability to block addresses actually is good one and do not reason for select other coin to hold.
The reason for this implementation is not for do some shitty things like a blocking regular users because of compliance problem in case of not enough tons of papers to prove funds/operations.
Crypto(as well stablecoins) are very client oriented now, not like a traditional banks who just follow stupid rules of regulators and do not respect clients at all.
Real reason for this implementation in contracts it's a ability to protect blockchain itself and users from massive hacks or frauds over some blockchain\contract.
In case some hacker will be able to harm blockchain\contract - his address will be blocked, funds probably recovered (if thing implemented), and other tricks will be used for minimize clients\blockchain problem.
I believe that few hundreds of thousands USDC that are blacklisted - it's a just block of funds that was tried to convert some public related hacked tokens via USDC.