I also see consultants just hired as bodies. Sometimes just to take on some work that you might not be sure if you want to hire someone full time or it's possibly temporary work.

I agree that good people at 3X is probably cheap. But the chef problem abounds. A talented person hires 10 people to work for him as consultants and the quality of talent declines with each person as the consulting business grows. I've seen people with less than a year or of experience billed out at $200 as consultants. They have often not had expertise in anything.