>>7164196851. Precise spacing
2. Movement that allows you to perform more actions than dashing does
3. Lets you immediately land on platforms
4. Lets you immediately slide off of platforms facing forwards or backwards
5. Some characters (Luigi, Ice Climbers, Ganondorf, Forsburn, Absa) specifically benefit from wavedashing because it's a better than their dash or run, or has niche characteristics
6. Makes your movement more unpredictable
Complaining about wavedashing is one of the easiest ways for someone to out themselves as a casual who doesn't know what they're talking about. It's far from the most important advanced technique - or even form of movement - in any platform fighter. It's like complaining about shimmying in a traditional, 2D fighting game. Just shimmying back and forth isn't going to get you anything, but it's still an important ingredient of good neutral and advantage state.