I don't think there is any valid way to judge the competency of a therapist. Education tells you nothing. Claims of past success mean little, because god knows how they measure success, and interpersonal chemistry is impossible to predict and is not replicable.

The only way to know if they are capable of wrecking things is by getting to the point where they have wrecked things.

I don't even konw what competent means. All the skills attributed to "good therapists" are vague and amorphous and could be possessd by anyone. Seems the main requirement is good acting skills.

The whole idea that there is a cadre of skilled clinicians whose training prepared them to heal total strangers by enacting a simulated relationship... gotta be one of the all-time great cons. In truth I don't think they know what the hell they're doing, and just wing it and hope they don't get exposed as a fraud or wind up in legal trouble. Or maybe some of them are so deluded they have no idea what is going on around them.