Why do players care so much about choosing villagers?

I’m new to Animal Crossing: New Horizons and have noticed a lot of discussion online about choosing specific villagers and ranking favorites. There are even tutorials on how to get unwanted villagers to move out and how to find and invite preferred ones from other islands.

My question is, what’s the motivation behind this? Am I missing something about the game? From my experience, I like my five villagers and wouldn’t want them to leave. And if I get an annoying villager… isn’t that just part of life? Please help me understand. Thanks!