So when philosophers use pessimism, what do they mean? Sometimes as a school of thought it is capitalized as Pessimism or Philosophical Pessimism. This is the kind I am also referring to with pessimism.

According to Wikipedia:

Philosophical pessimism is a family of philosophical views that assign a negative value to life or existence. Philosophical pessimists commonly argue that the world contains an empirical prevalence of pains over pleasures, that life is ontologically or intrinsically adverse to living beings, and that existence is fundamentally meaningless or without purpose.[1][2][3] Their responses to this condition, however, are widely varied and can be life-affirming.

Philosophical pessimism is not a single coherent movement, but rather a loosely associated group of thinkers with similar ideas and a resemblance to each other.[4] In Weltschmerz: Pessimism in German Philosophy, 1860-1900, Frederick C. Beiser states the central thesis of pessimism as "the thesis that life is not worth living, that nothingness is better than being, or that it is worse to be than not be".[5] In a very similar way, Schopenauer argues that it would have been better if life had not come into existence.[6] For many philosophical pessimists, however, this view of life does not automatically imply the desirability of suicide, but simply the gradual abolishment of suffering

But I'd like to further elucidate that it is not just about what is negative, but what is pervasively negative about the living, especially as a self-aware being. So, for example, a particular war might be contingent on circumstances and perhaps could be ended easily with X, Y, Z. However, it isn't a particular war that a pessimist would care about but the seemingly pervasive aspect of conflict and war in human society, governments, and history. It seems like a feature or an irradicable bug.

I wrote a previous thread about technology, for example. In that one, I described the pervasive and inescapable nature of the fact that not all humans can truly participate in creating the technology that sustains them. It is sort of a feature of how technology seems to work (at least anything past really primitive forms).

I wrote in another thread about the inability to move to another form of living. This is a pervasive and inescapable feature of being born. We cannot really change the set of choices and harms presented to us. We must participate or kill ourselves. Once the treadmill is started, there is no getting off. There is no rest.

I just wanted to make that clear before moving on.