What are the negative effects of population cap?

I just realized that you can actually set a population cap with the Dwarf Fortress LazyNewbPack. I made a game and set it to 50, I feel like that's all I really need to function efficiently and not make me want to slit my wrists (metaphorically), but I'm a tad worried about really late game and what might happen with the limits of such a small population when:

releasing clowns (e.g., "hell" demons) or fighting FB.

Is it necessary to have a large population to survive late game?

Solution 1:

Population size is a trigger for the arrival of some nobles and the features they bring, the least number of dwarves you need before unlocking all of the features is 140 (the condition for becoming a metropolis and hosting the monarch of your civilization). You can check the population requirements for various nobles on DF wiki. Some people would consider less nobles to be a benefit rather than a drawback.

I wouldn't say you need more than 50 to deal with the late game, because if that number is not enough then the fortress will crumble with more than 50 in any case due to tantrums. If you want to make sure your fortress goes on forever, have a couple dwarves in solitary confinement (surrounded by natural or constructed walls, floors and ceilings) with a small farm, some beds, barrels, a kitchen and a brewery, preferably fresh migrants so they won't know anybody and therefore won't mind if everybody gets slaughtered.