Starting over with a new T has its pros and cons. For some, they find a better T. For others, they don't find a T that matches with them. And then there's many other scenarios that are true too. Suggesting that one way or the other is best, doesn't mean either will apply to an individual. But if an individual has the wherewithal to keep trying, then it might definitely be worth it.

I have been with both bad Ts, mediocre Ts, good Ts, and great Ts. I went from mediocre to bad to great to bad. Took an 8 year break because of agoraphobia. Found a bad one, then a good one, and now a great one. For me, I needed a therapist's help. There was no other way for me.

My point is that everyone is different and everyone has different experiences. It IS a possibility that one might find a good T after a bad one.