There's a difference. BAck in ARR, leveling up was also getting a grasp of the overall gameplay, how tanking / healing / DPSing works in this new game etc.

Now two expansions in, we know how that works. We know tanks have DPS combo, agro combo, invuln, CDs, stances. Healers have Single target heal, AOE heal, DPS spells. Shield or Regen. We know that, all jobs are just "aspected" versions of roles. We know the core concept of roles by now.
So I'd rather focus on learning a proper complete rotation starting higher level that clawing my way through Sastasha with an incomplete combo or running around in PoTD pushing random buttons.