*twitch*

PvP was never a Final Fantasy element.
Full character customization was never a Final Fantasy Element.

The Jobs are based on equippable stones much like the Crystals of FFIII on.
The storyline is chalk full of FF tropes and callouts, right down to the theme of the crystals.
All of the basic FF Elements are there, Mootles, Magitek, Cid, Bigs, Wedge, Gilgamesh.

Every FF game varies the system somehow. To try to claim one as 'the' system to base Final Fantasy off of insults the series's trend of redefinition, in my opinion.