Diadem highlights FFXIV's biggest flaw: Lack of Horizontal progression

[Bourne_Endeavor]

Imagine instead of gear, Diadem offered legendary Materia that offered slight skill mods? Or enchantment stones that increased certain attributes for your gear?

Problem is, this will inevitably boil down to which is better. If the skill mod bumps your overall damage more so than the Scripture weapon. People won't farm for tomes and just farm for the skill mod weapon.