Its good that gil means nothing, it makes gilsellers less of an issue.

Gil is allowed to be nothing in this game. The real currency is tomestones etc, and because of the weekly caps SE ensures everyone is as rich or as poor as each other.

We don't want to go back to FF11 times where we defeat bosses for crafting materials and having to farm/mine/fish for a month to be able to afford the rest of the materials or to just go to the AH/Market Board to just buy the final crafted item.

Its also worth pointing out that FF14 has had an inflation problem before, and everyones gil was reduced from 1.x to 2.0 to a 1/10th of the gil they had.

That said, rich players should be encouraged to "reinvest" their gil

Charge players a weekly rent for their Housing
Charge players a weekly fee to use retainers
Actually have some decent gambling halls in the Gold Saucer
Add loot boxes lol

That would be a start.