Perhaps someone will start a new breed with sanity and stability as their main goal.
Starting a new breed won't fix anything. Just take a look at all the new "designer" dogs for sale (doodles and poos). I hope you don't think they're the answer to finding sanity and stability in a dog. Give it a few years, and your "new breed" will have problems too. GSDs have been a very popular breed for a very long time. That demand has led to poor breeding in an effort to chase dollars. Maybe the way to go is to find a rare breed dog with the qualities you want, and it shouldn't
have the over breeding issues the modern GSD has suffered from (but I think it may be tougher to find the rare dog breeder than finding a good GSD).