@ujm
Trained/licensed therapists have intensive supervision during training (and often throughout their career), have a professional certification to uphold, and there is a clear process to register concerns or complaints if they behave inappropriately.
It doesn’t make abuse impossible, but it lowers the risk.
Apart from that, if you ensure the therapist you are seeing is licensed, it means that they have never been expelled or excluded due to historic abuse. If you go unlicensed, you have no idea if he was chased out of a community ten years ago due to being an abuser.
Also, the therapy might actually work if they have been trained in it.