Very wrong. I have some familiarity with therapy, and in a way, community is actually detrimental when it comes to mental disorders.
Depression is a typical example. When somebody suffers from therapy, friends (community) will give all sort of cheesy advice like "relax, go out, do sports". This is detrimental because it's frustrating, but especially, because it triviliazes a serious problem (people not going to therapy because of stigma, when they should, is a real problem).
No amount of community can address a problem like depression, and this should be crystal clear.
Mental disorders, like serious illnesses, require a knowledgeable and systematic approach in order to be addressed.
Surely, modern isolation is causing mental health problems in the population, but community may be the solution to those specific problems, not to disorders in general.
> it's pure luck if you find the right therapist
It's not pure luck; it takes attempts.