My little company built such a thing but YC and others like them are very disinterested; it’s very hard to get traction for something like that because you are looking at millions of dollars in marketing before there is enough of a network effect to become useful.

And is also a very subjective market. A great therapist might be the worst for someone. I know of a few initiatives like this in Spain a few years ago, and the review/recommendations system always felt clunky.

Besides, some schools of therapy would think the expectations of a patient that expects you deliver a 5/5 stars therapy, would taint the natural therapy process.