The sanctions will also be blocking the legal crypto exchanges from dealing with them as well. So that isn't going to work either. You might respond that you'll just use an illegal crypto exchange, but from that perspective it's not the crypto helping you. It's the illegal exchange, which doesn't actually need crypto to function.

Edit: Also, there's a bit more to unpack here. The transfers from Russia are only a problem with RUB. If you can transfer another currency to them into an offshore bank account then it's not a problem. And I hope you don't transact in RUB anyway, that likely means selling the business back to Putin's war regime, unless you physically go over there and use the proceeds to help the anti-war movement.