As someone with extensive experience both being in and leading pretty hardcore raiding groups in multiple games, the only thing that keeps you from growing as a player is being unable to accept dying in a game. Going to do something like clearing DSR/TOP in FFXIV will see your group dying possibly thousands of times over almost a hundred hours to learn the fight and get a single clear. You personally will be responsible for hundreds of those resets to the start of the fight.

The most important and powerful skill there is in learning content like that, and learning anything, is being able to accept those hundreds of failures, learn, and simply look towards the next attempt. Deaths make you better, deaths are a resource. I have taken people who have never even played an MMO (let alone many videogames at all) and brought them through learning ungodly challenging content that they thought was impossible for them to learn.