Bit early to be coming to that conclusion, I think. FFXI has stood the test of time - it's lasted for more than eleven years and people are still playing it. Even if FFXIV currently has more players than FFXI did at any point in its lifespan (I don't know whether this is the case or not), that says nothing about where it'll be a decade from now.
Part of the fun of FFXI, imo, was building "Ultimate X Builds". You could look into an Ultimate Enfeebling Build for your DRK, which might require obtaining bits of armor from all kinds of different events. Or an "Ultimate WHM melee build" - sure, no one would use a melee WHM in a serious event, but that sure didn't stop people from hunting Shen, now did it? Being able to obtain these different sets of armor was part of the charm - and actually being able to USE them due to the ability to change equipment mid-combat meant that they could even be useful from time to time. "RDM's down, and we really, REALLY need to sleep the add on this boss! No worries, while a normal DRK might not be able to sleep that add, I have the Ultimate DRK Enfeebling Build!" The day is saved!
In FFXIV, there's much less option as far as Ultimate Builds go. If you're a DD, you build for damage. You don't even really have choices like "Skill speed vs Crit rate vs Determination", because it can be mathematically proven which of those stats is superior. If crit is the clear choice, and you show up with the "Ultimate Det Build", all you get is funny looks. Tanks and healers have a little more versatility; both can look to emphasizing dd roles in certain situations as needed.
Once you have your ilvl X gear from Dungeon Y, there's little incentive to go farm Raid Z for different ilvl X gear - especially if the piece you have is mathematically superior (and if it's not, you'll likely never even bother with Dungeon Y). On the other hand, if one dungeon gives your BRD a great dd body piece, and another gives your BRD a piece that's only average for dd but reduces the recast of Blunt Arrow by half, are you going to go for both pieces? You'd better believe it.