taken from a reddit post that might help explain why this is an issue:

if a game like cs go had netcode like xiv, it would result in that players with lower ping would have a faster fire-rate than those of higher ping players. imagine being at 50ms with an r8 and being able to fire 18 shots, whereas if you were playing at 200 ping, you would only be able to fire 14 shots. it works like this:

press ability -> animation lock occurs -> server confirms pressed that ability -> animation lock + your ping occurs, which is why the game feels the way it does at higher ping. now for those of you who live on the west coast/midwest where their ping isn't quite as severe, i'm glad and happy for you. but for the rest of us in NA who live on the east coast (northeast and southeast US players suffer much much worse).

there were a few interviews in the past where this was brought up to yoship and he seemed honestly blindsided by it and didn't know what to say beyond "uhh something something packet loss" (i believe this instance i'm describing is from the reddit AMA/q&a) and said they would be looking into it, though, there has not been much on that front in the year and a half since that interview.