Sanctions only are painless if the other side has no economic advantages against you, or otherwise has such a small economy that refusing their goods has no effect upon you.

Russia isn’t tiny resource poor Cuba. Everyone who refuses to trade with Russia suffers real losses as they are forced to get key goods from other sources. For central and Eastern European counties this is a real issue.

Imagine the US sanctioning Mexico… yes, it would hurt Mexico’s economy, but it would also devastate the economy of the South West USA.