So from what I understand and I may be a bit wrong here so correct me if i am cause im all aboot learning but Having a good connection speed doesnt fix a wireless connection.
Wifi cannot simutaneously download AND upload..so a lot of times if you reach a moment in a match thats heavy, it can cause a slowdown or at worst a complete disconnect. There are also a lot of factors that affect how much of your speed you actually get (ie other users, weather in the area etc etc). So just having a good speed doesnt matter if the equipment you have isnt able to utilize it. It's like putting the wrong type of paint on a wrong surface. Doesnt matter how good the paint is its gonna fall off cause its not in the optimal spot (sorry only analogy im smart enough to make lol).
Fighting games require such precision, reactions in a 10th of a second it is absolutely CRUCIAL if you want to be a top competitive player that you eliminate any essence of interruption, and I don't think its unfair of big organizers to ban wifi in competitive events. You don't see cod events or CSGO events live finals played on wifi, its all LAN. No reason fighting games should be any different.
Don't get me wrong, I used to play on Wifi for years and I was still able to compete, but I switched to wired and noticed a huge difference and havent looked back.
Packet loss is something i havent looked into enough to advise on, maybe
@Pig Of The Hut can talk more aboot that so we can educate the community but to say wifi can be as good as wireless in a competitive environment is simply not true.