As a city the one that sticks out is Vancouver because of a massive amount of training that goes on with indigenous artists (I’ve looked mainly at Haida or Tsimshian traditions). Either woodcarving or engraved jewelry, but they work in many other mediums too. Otherwise the pattern that I see is some lone genius that is in a major city by themselves, such as the iconographers Yury Yarin in Moscow or Anthony Gunin in Boston. But they’re all coming from cultures with longstanding traditions of art and building off of that.