Playing Crusader Kings II at very high resolution
This is a long standing issue with CK2 and related games. Paradox is too lazy to fix it, however there are several mods that somewhat mitigate the problem, for example this one https://steamcommunity.com/app/203770/discussions/0/846964364055605789/
While it probably won't let you do a 5k resolution, it would still be a huge improvement