True. But there is a hole in leveling between 8-10 (all secondary quests are used) and 10-15 isn't much better since XP from guild roulette is really low.
We have less skills to manage but leveling has some kind of steps :
8-10
10-15 (guild roulette)
15-20 (dungeon roulette)
20-30 (squadron)
30-45 (PVP)
After 45 and 50 with roulettes, tribes, PVP, daily hunt (and 70 Trust) it can go really but really fast. That's kind of a weird logic.
I know there is the Deep Dungeon but the system is way too rigid (some kind of two slots memory card is... kinda outdated?)