Nobody expected sanctions that cut Russia off from the world to an extent comparable only to North Korea. It's just something that people didn't imagine could happen to modern economies. People said cutting Russia off from SWIFT was absolutely unreasonable, impossible, and nobody would seriously consider it. Heads of state said they'd never do it despite the circumstances. Then they flipped and approved of it.
It's easy to look back and say "lol it's obvious" since it's in the news everyday and we're densensitized to it by now. But it was really a mindblowing series of events.