i think you guys need to realize a few points.

the game is ment to get you to 50 asap, so you can experience the story and end game.

but however if one wants to level anther job SE wanted this to be slower.
they dont want you grinding fates? THATS BORING and they know it.

so that leaves.

Hunting log
Leve(save these for crafting imo)
and DUNGEONS.
they wanted you TO GRIND DUNGEONS REGARDLESS THAT EXP IS LOWER THAN FATES.
this fills in party roles for people who are still on the story.