The Townie eps can still be enjoyed as their own individual stories, with some having an added moral regarding familial, platonic, or romantic relationships. Townie eps can either be funny (“Rising Tides, Crashing Skies”; “Restaurant Wars”) or emotionally charged (basically any LarsxSadie episode).
But if plot really is all you care about since cartoons can’t just simply be enjoyed as a short, one-episode story, many of the Townie episodes still have underlying plot significance by introducing more of Steven’s powers, adding more worldbuilding, or even throwing hints at how Gems have affected Earth.
"Onion Gang" is literally the only skippable episode since it isn't that entertaining, it's visually boring, and it doesn't do much as far as worldbuilding is considered. Watch everything else.