> Wait - so unemployment is bad. Unless enough people have jobs, then it's good?

Yes.

The ideal amount of unemployment isn't zero. People quit jobs and move to new cities (sometimes following their spouse who gets a new job) and then look for work there. People upgrade their skills. There are a lot of reasons people might temporarily be unemployed. If they don't have the freedom to do those things, that's bad.

If the unemployment rate is zero, that also means that there are jobs that literally cannot be filled and are not being done. That's bad too.

Obviously, an unemployment rate of 20% is also bad.