Bizarre takes on using wifi in here. I use wifi and Smash is literally the only game that gives me lag, sometimes.
The quality of your connection from the node, not using the wifi on the modem from your internet provider, the distance and interference between the wifi router and your device, plus keeping the frequency clear while you are gaming is all you need.
Btw, everyone in here has a wifi router that is separate from the modem and allows you to use several different frequencies, right? Right?