How to make the game better for new players?

[Vahlnir]

From a game development perspective, I think that when we sync down to level 70, 60 or 50, we are doing the SB, HW or ARR rotation respectively and that content was designed and balanced around the type of actions available in that expansion. Even when adding new jobs, there seem to be actions that are intentionally not added at the lower levels because other jobs don't have them at those levels and it would imbalance certain content.

I disagree. It is gear that makes old content imbalanced. Look at the Crystal Tower raids. Or Void Ark. Or even old dungeons synced down, with players still having an edge just because of their gear. That being said, they should have tweaked the boss HP levels or something to reflect that growth, but they did not. If anything, our characters are way too strong in some instances and could use some nerfing in the form of a lower synced item level. The Ivalice and Nier raids are much more balanced in this regard, though that doesn't completely stop players from steamrolling through Rabanastre. I'm guessing all of this is at least a small factor in their reasoning to perform their future stat squish.