The big problem here is that the game has gone through so many iterations and each tier has a skill cap. This is why content like Aurum Vale (synced) still wipes unsuspecting groups to this day, despite being face-roll to anyone in decent gear. In other games, once you max level, your skill set ultimately remains the same no matter what level the content is. The damage is just scaled down. Because the Endgame community only cares for the most current content, and also because the game itself has changed (sometimes vastly) from previous iterations, it's almost impossible to find guides for the main tiers (50/60/70 along with 80) that are current and useable for players to reference.

Usually only optimized rotations are referenced when one goes looking and find me the sprout that can get their head around using pots in their rotation when they are struggling to kill mobs in a fate or in a story quest. And Tool Tips are notoriously unhelpful. Especially to someone new to MMO or even just new to FFXIV. Knowing what a skill does in a very basic way does not tell what order said skill should be in a rotation.

So in short, I agree that the game does little to teach people to play. That is largely left to the community. Whether online in guides or in duties with other players. And that ball is dropped. A lot. I get why but having been the person that explains things to an entire light party/full party/alliance and subsequently getting us through the content, well... The risk is worth the rewards IMO.