You don't have to rely on leaves from 1-50 and depending how you want to level, not at all. There are random camps all over that work really good for 30-40 and once you hit lvl 40 you can go Uber fast (TOO fast in my opinion) if you go into the beastmen camps. Nice thing about the beastmen camps is you can ket tapers for Ifrit at the same time if your needing them.

If you want to PL you can easily PL from 1-30, but as stated above leave quest will get you from 1-20 or 25 pretty quick then you can grind to 30 and get a good party. Honestly I think using leaves as a brand new player to the game would be a good way to ease in and learn the game mechanics without worrying about finding camps and knowing where good spots are.

But yeah if you are using leavequests to go from 1-50 I can understand you are bored and find the game lacking.