>European companies suffer 100bn euro hit from withdrawing from the Russian market
there are now more people saying that the sanctionists are retards, but the reason is usually that this is only the sanctionists were wrong about the exact state of the Russian economy. Their lesson is "sanctions might be a good idea in general, but not against Russia"

This is a bad lesson. Sanctions are retarded in general. It is not that there are some rare cases where they shouldn't be used, but the reverse: you have to tell a high fantasy story in order to establish a case where they should be used.
1. trade is mutually beneficial. You have something. Another guy has something else. Both of you prefer the other thing to what you have at the start. Post-trade, you both have your preferred thing. You are both better off.
2. but what if the other guy uses his gains from trade with you to war against you? You also have gains from that trade, so you can also use those gains. Cutting off trade makes you worse off, and you still have war.
3. but what if it's an island nation and I'm their sole trading partner and I'm selling them ammo and they gain much more from trade than I do and and and -- this is a "high fantasy story".
4. but surely sanctions are good to prevent a military buildup! -- yeah, super good, just look at how it prevented WWII from ever happening: https://en.wikipedia.org/wiki/Ersatz_good