FFXI's gear swapping is a whole bag of issues when it comes to gearing up, instead of having a set of acceptable gear you have to have ALL SETS and the game was horizontal lol. Nightmare easily. However I would like to suggest looking into WoW if you're only focusing on gear having interesting affixes, since FFXI may be harder to peal apart due to the can actually use everything .. thing (like I had macros for individual spells, whole gear sets for single spells - sometimes I would just flash through the whole battle XD).
WoW is definitely far more linear in growth than FFXI and they not only have ability affixes but they have a lot of them through relics (basically special materia), enchanter, and items (trinkets almost always having something nifty to them). Its true certain abilities and trinkets are trash, and sometimes the options become super freaking specific --- BUT, as it is linear most of the time it is upward while still having what I guess I'd call breath mints, the ability affixes can freshen the game's breath after certain hours of playing around with mechanics.
Because of a certain set of weapons I acquired for like 5 levels I had a melee hunter because it literally did more damage lol.
Affixes do not have to be associated with horizontal progression, although I would like to see semi-horizontal so I don't go from one primal to the next with each one before it always being entirely trash items. FFXI was (was) years of horizontal, I'd rather not have that because it really makes end game for those who have A LOT OF TIME (something your GF is probably picking up on, which is less to do with affixes and the fact that it is both horizontal and you could gear swap).
So I'm not saying she didn't have issues, I'm just suggesting a major portion of those issues probably came from that you can gear swap and there was a big wall of horizontal content. So you want one staff for this spell, another staff for that, this chest for swiping with your sword, these for TP, etc etc.