I have never had much faith into "evidence-based" therapies, especially when you have a complex condition. It's obvious that in order to just show basically anything with a reasonable effect size regarding something as complex as psychotherapy, it is absolutely necessary to simplify it to the point where the results become statistically significant but in reality are completely useless.

I do think that psychotherapy has quite many similarities to science though, I mean the process in general.

First of all, in both science and psychotherapy, you actually don't know what comes out or if anything good and useful comes out at all. You start with a certain amount of faith that there is a chance for some success.

Secondly, both scientific and psychotherapeutic processes require quite a lot of resilience. Most probably there are periods where you have to endure uncertainty and not understanding what's going on. But in order to get something out you have to keep trying. You try one way - it doesn't work, you try another way - it doesn't work. Finally, during this process of trial and error you have hopefully learned enough about your problem that you are finally able to gain some useful insight about it. But the process is neither linear nor clear but is very satisfactory and rewarding if something finally comes out - both in science and in psychotherapy. At least this has been my experience with both of those disciplines.