No. Biological theories of mental health and mental illness are very much established.
And yours is a complete mischaracterization of the work of Kirsch et al.
Their meta-analysis found that in ALL cases of depression, there is statistically significant improvement in quantitative measures of depression treated with SSRI. In moderate to severe cases of depression, the improvement was clinically significant (ie a clinician and patient clearly note the improvement). The meta-analysis done on clinical trials were overwhelmingly trials of 6 weeks of SSRI or less. Suicidal patients are almost all excluded from such trials. Treatment groups were treated with SSRIs via research protocols, and not usual clinical practice: there were no attempts made to match patients to an SSRI that would be most likely to help, to wait on a response, to use SSRIs that were helpful based on a family history; dose adjustments were typically prescribed by study protocol and not by patient response, patients were not switched to another SSRI when there was no response or if intolerable side effects developed, often no attempt to treat side effects with other agents were done, etc. In other words, none of the things any physician routinely does to optimize treatment were done in those trials, and yet there were STILL improvements in measures of depression across the board.
No reputable psychiatrist or physician will fail to recommend an SSRI in cases of moderate to severe depression. Therapy can also be helpful, but the evidence is overwhelming that SSRIs help in clinically significant ways in moderate to severe depression. There is no credible doubt about it.
Despite your assertions about what "people very much want to believe" - in my experience, people very much want to believe that the brain is somehow different - that something beyond biology is at work. Believing that somehow depressed or otherwise mentally ill people can just "snap out of it" or "pull themselves up by their bootstraps" is erroneous, unhelpful, but fits nicely into really completely shitty and cruel narratives about human beings.
But please. Perhaps you'd like to advance a theory on how an organ like the brain differs from every other organ and does its work in ways not explainable by biology, chemistry, physics, etc.