Villagers in your camp will give you stuff hourly and you know that they're always there. For example, I'm low on cotton so I've put Tex and Maggie in my camp because they always give me lots of cotton, sometimes even just for saying hello.
Unlike the travelling animals, villagers in your camp don't have to have a specific request for you to get items or money. Just say hi to them.
yeah if youre lucky and meet them a lot. it's still good to have villagers in your camp but you gain more friendship for finishing requests than from talking to them in your camp. i have unlocked all 40 villagers so i find that having villagers i want to level friendship with in my camp is useful but if you are at a lower level with fewer villagers i guess it'll be different.