No, why would they be?

None of the three I've seen recently took insurance, and there was a range of quality among them - two good, one meh. The one I saw in college, who did take insurance, was also meh, but better than the meh one who didn't take insurance.

Think of it the other way around, in just as stereotypical a way of reasoning: insurance companies don't like paying benefits. They want results. They are unlikely to fund visits to ineffective practitioners. Therefore only bad therapists don't take insurance. But we know that's not true, so why would the reverse be true?