More interesting loot please! Here are some ideas!

[kyuven]

Her point is moot anyway since FFXIV doesn't include in-battle gear swapping.

Not exactly. You may not be able to swap in combat, but if you have items with certain effects you will be expected to have these items for the specific situations, and have them equipped during those situations.
For example, the aforementioned proc'ing fire bracelet would be REQUIRED for dungeon runs where defensive stats are less important than DPS, meanwhile anything that futzes with defenses will be REQUIRED for the bosses.
And once again I must bring up the point that FFXI never really addressed with sincerity and that this game is, by the dev's own admission, suffering from: Item storage space.
Starting next expansion, there will be 23 classes in this game. There are currently 25 slots in the armoury. Having "more options" for gear sounds "great" on paper, but we simply do not have the space for all those gear sets. Even if SE does expand the inventory, we will NOT have the room for as many sets as adding "fun n crazy" items would require.
As mentioned in my EQ1 example, this created a LOT of problems.

Materia should be just stats, some crafted gear already has an advantage a bit.

However, there can be other ways to do it!

They can be items you equip on your character to give them unique procs and such.

This would be a more practical solution, so long as these items are balanced. Things like "Decreases MP consumption of Foe Requiem" or "Decrease recast time of Benediction" or "Increase Mana Regen of Shroud of the Saints by X%"
Stuff like that.

Are you implying that isn't the case right now? Every class has one set of BiS and everyone (who can obtain it) is wearing it. There is zero customization right now.

Not every class has a "fixed" BiS. There is some wiggle room to better fit personal playstyles, and the fact that there are plenty of options to attain those builds. It's not as robust as a lot of other games, but it doesn't NEED to be. This isn't Champions Online or Rift, after all. For some class certain stats just aren't worthwhile, rather than lacking options.