The best part about is I think all the characters Yingyay mentioned as 'high tier' are all in fact very solid characters. Arguably some of the bests. But at the same time I could argue for Falco, Luigi, ZSS, and maybe Falcon as well as many others could be there too. My point is that you can ask just about anyone that has been playing Brawl+ for a long time and they'll have different opinion.
Sure, some characters like Marth will always be regarded as one of the best but the point I'm making is that we really don't and probably won't have a standard tier list. Every character has their strengths, weaknesses, good matchups and bad matchups and I feel we are really close to a game where a skilled fighter should be able to overcome their opponent.
That being said, the demand for a tier list will eventually make the community cave and I'm sure a list will be made, but the inevitable matchup chart will be a much more reliable way of seeing how your character stacks up.