If MKLeo, Kreeg, Ignaize, Rizeasu, and Mr. E ALL dropped Marth, WHY should I main the character and expect to get results?

If the best of the best couldn't make this character work why should I bother trying? Everyone wants to act like I can win a regional with anybody but Marth doesn't do crap even at THAT level. Ganondorf won a C tier before Marth did in the last year btw. GANONDORF.