Yeah, calling depression a "disorder" sometimes misses the point entirely when despair is a logical response to how things are
Regardless of how bad things are, we still have hope, both as individuals and as a civilization.
My partner is disabled and her transplanted kidney is failing. She will, in the next year or two, need dialysis and then a kidney transplant. Her Medicaid will be cut. The hospital she goes to will be closed. Both as a result of a bill that just passed. The average kidney transplant out of pocket costs $250,000, and because her first transplant happened before she met me, my insurance will deny her coverage because it's a pre-existing condition. We are in the process of trying to move to a different location, get her a job while she's going through kidney failure (not easy since nobody wants to hire a sick person, and definitely not at a workload that would give them benefits), and I'm in the process of trying to move us out of the country (I'm a dual citizen, she is not, so that's holding things up).
At what point in that is despair not a logical emotion, even when we're doing something about it? What is illogical about being so overwhelmed with circumstances that it makes you question whether waking up tomorrow is a net positive or negative? Please explain.
No we don't. Evidence: falling birthrates is the society collectively deciding that live ain't worth it. Personally, I think this is the real reason why we don't see aliens - any advanced civilisation will eventually reach a point where it realizes that life ain't worth it.
Adopt absurdism. Nothing really matters and it's grotesquely hilarious at the same time. That might cheer you up. Occasionally.
Recently I heard Neil Degrasse Tyson saying that people came up with averages more recently than with calculus. It's not something people find relevant naturally.
Whoa now. That may be true within a strict scope of the "arithmetic mean" definition of "average", however, the idea of average as a 'concept' is much older. As an easy example, early references to agrarian yields (crop farming and how much food they produce) talk about average size of crop harvests, etc. Early tablets from Mesopotamia talk about average yield size, and those are dated 700ish BC.
Slightly more seriously, things will be on an upward trajectory until they aren’t. There are some decent reasons to think we might be nearing the peak.
There is a significant meaning to my claim, which is that it's unconvincing to make exactly the sort of "it has always worked out before" argument that you're making here.