It is not so simple to know what is and is not a good therapist. A common thing people in therapy hear - from therapists and from others - is that it gets worse before it gets better. It is not clear which worse is the right kind and the wrong kind of worse. Plus not everyone goes for the same things. It may be relatively easy for someone like me to change therapists and see a lot of them and use them in an unorthodox manner. My life mostly works pretty well and I only went for a small hitch which therapy has had no bearing on - but I found a different use for the woman. But others, with things like less disposable income, more serious or desperate situations, less outside support and so on with various combinations, are caught a little bit more sometimes
I have no idea if the ones I see are any good. I managed to make the first one work better than she was and the second was always sort of harmless -- but that does not mean they are good therapists - just that I have found a use for them.
There are very few guidelines or information on how it is supposed to work, there are lots of different approaches with fans and detractors, and often when the client asks - they are told the therapist has their best interest at heart, should be trusted and if it is going wrong it is the clients fault and the client is not doing it correctly. How then is the client to know?