But PM didn't balance out everyone, it only made characters more viable, and even then there are still clear disparity amongst characters. ZSS, for example, struggles with fast-fallers and disjoints. Fast-fallers like Fox and Falco, change up how ZSS has to play due to a lot of her combos not working properly on them. Marth and Roy beat her out due to their better range, again, forcing the ZSS player to think differently about their approach.
The only way PM, or any game for that matter, could achieve true balance is if every character were the exact same. Considering PM is trying to make each character unique, no matter how much they balance it, one character is going to be more advantageous against another, forcing the disadvantaged player to figure out how to beat the advantaged one; basically like Melee...
And what does being a mod have to do with anything?