I'm not a psychologist, and anything I could say on the matter should be taken with an entire shaker of salt, but I think that the way we understand inner well-being - and the language we use with regard to it - are somewhat imprecise and misleading.
We call it mental "health." Those who have studied it are "doctors" of psychology/psychiatry. The chronically melancholy "have depression." But it's fundamentally quite different from other fields of medicine. It isn't nearly as cut-and-dry.
I'm absolutely NOT saying that it isn't as important to understand or that professionals in the field aren't doing the best that anyone could presently be doing or that those suffering from what we're calling psychological "disorders" aren't truly suffering. What I mean is that state of mind isn't as simple as physical health, and lived experience isn't as simple as medical pathology, and to view it through the same lense and attempt to solve its problems in the same ways is somewhat counterproductive.
A "healthy" mind is defined by its ability to function within society, but we never say that society is "sick" when a significant portion of its people are unable to function in it. We underatand there to be a "typical" neurorype, and others are "divergent" from that ideal model. I think that this is a flawed understanding, and the best treatment that can be devised through this line of thinking is akin to a band-aid.
I would compare modern psychologists to surgeon-barbers during the time of the black plague. They truly wanted to help, and sometimes they accidentally kept people from infection, and their efforts went on to inform what would become the study of medicine, but they did not have a working understanding of the condition they aimed to remedy, and that severely limited their effectiveness.
All of this is to say that, though we may be chronically and debilitatingly unhappy, I do not believe it is correct or useful to say that we have acquired a malady that has a traceable pathology that can be treated or cured through conventional therapies, as we understand them. We're letting blood because we don't know about the fleas.