Hi Daranion,
The first thing to make it a possibility would be Yoshi P and the Dev Team making various Secondary Stats more meaningful (matter more). In addition, opening up additional Secondary Stats (not too many, but even 1 - 3 more parameters would help).
From there you could have more strategic and interesting ways to decide between different sets. I like Nalien and Nek's ideas above. Some other examples:
(Note: Only IF various Stats were more meaningful in battle, and there were new Stats as well.)
Tank Sets (Same Item Level)
* VIT / HP Tank Set: This set yields the most amount of HP / VIT, basically like a "Blood Tank" in a way.
* Damage / STR Tank Set: This set focuses on more STR doing Damage. Some players might enjoy tanking with Less HP / VIT but at the cost of more Damage (we see some of this currently with HQ Crafted Jewelry swapped in).
* DEX / Block / Parry Rate Tank Set: This could focus on affecting Tank's Block Rate / Parry Rate (to more meaningful levels (and it would entail messing with Magic Damage being affected as well)).
Back in 1.0, when Block Rate / Block Strength on various Shields were a thing, there were interesting discussions amongst Paladins about the advantages / disadvantages to various Shields (some had Super High Block Rate, but Low Block Strength; others had Low Block Rate, but Super High Block Strength (so more damage was mitigated if it proc'd)).
* Tank Sets with Unique Stats: Maybe a new piece of Armor or a Set that adds in:
*** Enhances Rampart. Causes Rampart to be projected to all players within an AOE around the Tank.
*** Counterattack +X%. Every time incoming damage hits the Tank, they have X% Chance to proc a "Counterattack." (Final Fantasy VII had awesome Counterattack Materia.)
etc.
The idea above is that various sets have Advantages and Disadvantages to them. Some players feel more comfortable with More HP / VIT; they might not have as reliable Healers (or they PF / DF a lot), or just want that buffer room. Other players might prefer having much higher Block / Parry Rates (if it affected Magic Damage also).
Others might want to give up various pieces of the above sets just to have Counterattack + X% Bonus Enhancement. Or "Enhances Rampart" because of their situation, or they just like to be able to shield more players around them in various fights.
But no matter what, ALL of the sets above would be the same Item Level. It's new interesting ways to gear. And unlike what we have currently, it's NOT worthless just for "Glamour" when it's released. If you don't end up getting all of say, 1 set of Gear, the next Patch with one of those Alternate Sets of Gear would NOT invalidate your Set 1 Gear, since it'd be Same Item Level, just different types of stats.
Other types of enhancements and unique stats from older Final Fantasies included stuff like:
* Adds Regen Effect
* Enmity +X
* Steal +X (when Thieves could Steal items)
* Evasion +X (not just for Tanks, DPS or Healers might consider more Evasion pieces to help avoid various bad situations at a tradeoff for other pieces)
* Conserve MP
* Double Attack +X%
* Increased Magic Defense (obviously at the cost of something else).
* TP Recovery
I'm not saying all of these effects are viable or useful the way FF XIV is now, but it illustrates the potential for *far more interesting* ways of Gearing than the awful, boring Gear we have every single patch since 2.0 launched.
"Yes," it would take some rework. And I'm not expecting or asking for all or even most of previous Final Fantasy effects to be added, but even just a few more additions, would be interesting and make gearing more strategic, and slow down Gear / Stats Inflation dramatically.
And again, in a Hybrid approach, the Dev Team can still upgrade Item Levels every so often, but it just doesn't have to be every 5-6 months. There'd still be new gear at the *same pace* as before, but instead of going
i90 > i110 > i130
it would instead be:
i90 Set 1 & 2 > i90 Set 3 (Unique Stats) > i110 Set 1 & 2 > i110 Set 3 (Unique Stats) > etc.
Lastly, the player wouldn't need dramatically more Inventory space: Yoshi P is *already* giving us X# of Gear Sets every major patch. But instead of the 90% worthless (stats-wise) New Dungeon Gear (that's just for Glamour), players would be earning Alternate Gear Sets (and picking and choosing what pieces they like from each one). Same volume of output as before.
Thanks.