While this advanced mechanic is back, it’s more situational and character-specific.
One of the most contentious mechanics that has returned in Super Smash Bros. Ultimate is wavedashing. While this was something players needed to learn in Super Smash Bros. Melee, later games did their best to eliminate it — before it has finally returned, in a more limited form, in the latest game.
Limited is the key word here, as getting consistent wavedashes seems to be much harder in Super Smash Bros. Ultimate. This is part of what this new video from Wizzrobe addresses. Here, he shows an alternate way to do wavedashes to get them more consistently.
That said, this is only part of the video. Wizzrobe also discusses how wavedashing is much more character dependent: not all characters have a good wavedash, so not all players may benefit from learning how to do it.