It's hard to answer objectively since they are all utter sh*tholes, but apparently on the rise.Folkestone has a decent seafood restaurant in Rocksalt, Ramsgate is at least showing signs of emerging from its dystopian past, Faversham I haven't been brave enough to drive through since 1984.
What about Broadstairs, Deal, Whitstable, Canterbury? I haven’t been to any of them in decades, but they used to be better than the places listed.