In tournament play, only certain attributes are needed. All others are irrelevant. So, characters can be well balanced, but can't compete in a competitive enviornment because their traits aren't needed. Take Meta-Knight. Meta-Knight attacks fast and moves fast. He has good mix ups and a good recovery. Even if all his attacks were weaker, he'd still be an A character because he focuses on what competitive players want: a fast characters. Ganondorf is a powerful character and almost all his moves are KO moves, but he's slow. Raw power is not needed in competitive play (as you can see, only Snake and Dedede are really powerful, and the later is up there due to chain grabs, not power).
In 4vs, every trait matters in it's own way, and it really more how you use them. Ganondorf doesn't need to be fast, the stage is small and everyone has to fight. Also, everyone is damaging everyone else. Ganondorf needs the finishing blow (fun fact
ower is probably the best trait in 4vs, at least vs raw speed. Ike is by far the best character in 4vs as he only needs to be right once.) Speed characters are still viable as they can run up to someone like Ganondorf and try to suppress him with speed. So, both dynamics work.