There's this thing floating in my mind for some time. A colony management game, where the colony is regressing instead of progressing.
You manage an isolated colony on a deserted planet slowly falling apart, desperately trying to mitigate the damage and survive the fall.
You begin with automated system managing the colony, so that you won't get overwhelmed by all the systems. Then, systems begin to fail one-by-one, by external factors putting them in strain.
Maybe the colony train network goes down first, then the communication network breaks down, leading to civil unrest. Next, heating fails, then environmental shielding, and oxygen goes out. You can utilize emergency systems and construct makeshift components, but it can only lessen the impact, not reverse the entire breakdown.
Maybe this is uncommon because sense of despair makes it unfun, but I would still find it interesting.
In case of math literature, I'd say it is mainly because the equations would be horribly long.
Things like integral computation comes with lots of details, or some kind of long exact sequence. Experts would have trouble understanding it, while normal people almost certainly have no interest in understanding the formulae.
Also, often there is no meaning to the variable. Like, in a real function f(x), x is just "a real variable". There is no additional meaning to it.
As for other fields, I dunno. They might have copied math literature style or something.
Interesting, I guess this is pretty explored idea in survival genre.