I’ve read that at least in the case of some EU banks, not following the foreign sanctions is quite literally not an option for them.

If you don’t follow sanctions, other banks either with branches doing business in the U.S., or their partner banks, will refuse to continue banking with you out of fear for not following sanctions – which include banks enabling sanction-circumvention. Essentially, even if the bank doesn’t want to deal with USD (which most banks would still like to do!), you’re still bound by the sanctions. A bank won’t survive long or well if it’s cut off from a majority of other banks.