One of the benefits to the current level synch system I think people overlook, is that it provides new players examples of what classes play like at their level. And this really only hit me because I have 2 friends who just picked up the game.

One of them was a WHM. In dungeons they would do little beyond heal spam, but in open world content they would use repose, stone, repose, stone, repose, etc. to keep themself safe.
That is... until they got into a FATE with another WHM, saw how they were playing the class, and went "OH!"

My other friend was a SMN who was constantly overapplying their dots... until they were in a duty with another SMN and saw how the more experience player was playing.

If the other SMN or WHM had their full kit (or even more of it) theres no way my pals, still trying to learn the low level stuff, would have been able to see what those players were doing and understand it, let alone learn anything from it.

And considering they've both made it through ARR, who knows how long they would have been stumbling along like this before it started causing problems.