What do you do with Townies?

I do a mix of stuff with them. I normally ignore most of them but my sims end up interacting with a few of them (neighbors, lovers, just friends, besties, etc.). I only delete the ones that don't live in houses that my sims don't know and that I don't plan on making them meet since I don't want my save to get laggy with them. (Like single, childless elders that don't live in a house most often since they can't breed and have no use basically since I feel it's weird for my younger sims to befriend elders but also sometimes adults or young adults in that category as well.) I do keep the ones living in the houses since my sims can have neighbors, but I might evict them if they're living in a house that I built/placed down or that was a premade one that I liked. I definitely keep families, though. Families usually have kids that my sim kids can be friends with (and find a potential lover from?)
If I feel like it, I just combine them into the same household since I feel like separate households is just too many households. I only kill sims for stories and such, or if it's for testing mods. As for makeovers, I only give them makeovers if they join the household or are important sims to me. I might change the facial/body shape if they're planning on having children with my sim since I don't want to get ugly children, haha. Otherwise, I don't care how ugly they are. :D

Basically, I just let the townies spawn since I usually manage to find a use for them in the end in all stories, regular relaxing saves and challenges. :)