I was coming here to say pretty much this.
And I'll 1 up also..
If you won't take materia out as implemented, offer actual useful benefits for varied materia builds. The system as is is just a shell of what it could be, and offers very little except a little meaningless step before moving on to a little more challenging content.
At no point is there a "need" to slot materia before "end game" but gear is riddled with slots to put it in. People level so fast and get synched so frequently that slotted materia on lesser gear is useless for the most part.
By adding legitimate reasons to use other materia builds it just adds some layer of desirable compexity.
