[KoenDG]

>It costs a lot of money and people-hours to interview someone.

True. Doesn't mean they're managing it properly.

>no company is going to waste the time and money to go through 3 interviews with a person

Again, assuming the company is carefully keeping track of this.

Sounds like an "ideal world" fantasy to me. Yes, the situation you describe is how things would ideally be. But they're clearly not. This happens, a lot more than many feel comfortable admitting.