I want to say Satori by virtue of everyone hating her, but she has her pets who are pretty much people.
Maybe Kogasa? I don't know how much interaction she gets from her blacksmithing job. Hina would be a good pick too, nobody wants to interact with a misfortune god. I don't think Alice fits the bill though, she does interact quite a lot with Marisa and others, which isn't a lot, but enough to not put her at the very bottom of the genso-loner hierarchy at least.
Or it is >>49850136 after all.