No breed of dog should exist because people shouldn't intentionally breed dogs. It's inhumane and most of them wind up in kill shelters. If you want a dog, adopt a mutt from a pound. It'll be healthier and happier than any other dog you could get. That said, breed characteristics are something pushed by dog breeders themselves. The actual science suggests dog breed has little to no impact on temperament. https://www.science.org/content/article/your-dog-s-breed-doesn-t-determine-its-personality-study-suggests