Step back that people don't realize is this though, why does XIV have more inventory space? Because unlock other mmos where let's say they use the same amount of slots, which mind you we have an armory chest for we have the following going on.

21 different potential gears to work on in XI

Most MMOs only have to worry about maybe 2-3 gear sets based on the type of MMO but for the most part let's put that into perspective.

Say an MMO, one class, one person, 11-12 based on offhand, so let's just say 11.

FFXIV 11x21= 231.
Other MMOs 2= 22
3= 33

That adds up a lot, because we only need 1 player to play everything, that adds up to issues with inventory overload, if this was any other MMO let's say in an MMO where you have 100 slots. then you have this. at most 33 is for gear, and then the rest for storage. In XI you already are using 231 for gear, 300 armory chest and 100 inventory, 400 inventory slots.

If this is still true, WoW inventory spaces are :
120 total bank spots
147 Inventory spots

267 total. That alone doesn't even equate to how many slots we use in the armory chest for all our job gear.