It's amazing how much stuff there is with the level of polish maintained. I do slightly miss some of the stuff that was cut, but realistically, I doubt I played any of that for more than 20 minutes. The amount of depth in World of Light is astounding for something that is at most a 3rd of the whole game. The online is my biggest complaint, but with the type of game it is, there's not all that much they can do. It's a fighting game, so every frame for every player has to be synchronised, where other games like Mario Kart can fill in the gaps. Australian internet over WiFi doesn't help. Having a specific classic mode for each character adds loads of replayability to the mode, and some of them are insanely clever. The core Smash mode has so many awesome customisation things like custom balance, stage morph and hazard toggles.
But that's just a theory.
A gaaaaaaame theory.