Almost every companion has 3 missions throughout the game, most of them are not even 5 minutes long (even if you count the dialogues).
I suppose that’s true, but to experience that 5 minutes one might have to go through 10+ loading screens (which were lengthy on my old machine) slowly slog through the world map, deal with multiple random events and rests, get to sort the kingdom management mess while you are at it etc. that’s a bigger Kingmaker problem, padding maybe 40hours of worthwhile content into 200h long slog.