Ways to make Gil?

[Nixxe]

Is the only way to make gil efficiently is by gathering jobs?

Gathering is for poor people. It turns time into gil at an inefficient rate, albeit a rate that's better than just about anything you can do with a battle class (besides run 8 person maps efficiently, but that still requires crafting for maximum profit). There are times certain nodes are worth hitting for basically anyone, but those are generally very limited opportunities and don't last long.

Crafting is a step above gathering, provided you know how to use it effectively.

Flipping is the true endgame. It requires the most investment of existing capital, but the least amount of time and yields huge profit if you do it well.