FFXIV responsiveness is awful, and I always felt it could be improved a lot, to the point that high pings would not prevent us anymore to reach the best DPS potential of our job.

Smashing buttons with no response, during what seems to be an eternity, in savage raids, in order to trigger an ability, is very frustrating. It feels like you need to wait for the server permission for most of skills, and it feels dumb, pointless, irritating, and even discriminatory as to why some abilities have such a bad responsiveness and some don't, why can't they all be responsive.

I'm praying since a long time in the hope SE will modify the Netcode in such a way we get full smoothness and responsiveness when clicking buttons, pressing keys. I have some friends who tried FFXIV and couldn't bear its bad responsiveness in fights and they didn't want to give a chance to the game.

High pings shouldn't be an issue with an optimised Netcode, the problem lies within the Netcode, not the pings, as long as they stay below 250ms, anyone could be able to reach the full DPS potential of their job.
This is a serious issue, that we can feel all the time in the game.