If people want an item bank in XIV, then they have an awfully short memory.
FFXI: Personal inventory - 30, after 10 wallet0destroying gobbiebag quests: 80
FFXIV: 80 slots up front, maybe quests to expand later. You can also store 12 in bazaar
FFXI: Mog House - 50 spaces, after expensive and time-consuming mog quests: 80
FFXIV: Retainer has 80 slots up front, and can be set up as a bazaar to sell 12 more items.
After that FFXI had Mog Lockers and furniture and armor NPCs, but that was all added later on, and usually only attainable by higher level players. As it stands, in FFXIV you have 184 starting inventory slots (if you price the bazaar insanely) AND crystals are not counted against you! Compared to FFXI where you had 80 total, and you couldn't sell anything from Mog (though there was AH.)
Having dealt with FFXI inventory for so long, the inventory here is luxurious. I DEFINITELY don't see what an item bank is needed for.
Apples and Oranges: FFXI didn't have +0, 1, 2, and 3 on every basic mat, nor did it have parts to make parts to make finished products. The crafting system has more depth and breadth, such that it uses far more space.
Plus, if you want to make use of the job-switching they tout as being a innovative new job system, be prepared to carry extra gear sets everywhere.