Back from Rift....

[Malakhim]

No one said you're stupid. But I've seen that question asked very, very rarely (if not never) with an honest intent. I'll give you the benefit of doubt though, and I'll give it a start (since I'm limited on time, and explained it too many times for it not to be boring), I'm sure others will continue. The armory system is a quite revolutionary innovation, as it's the only class-based system that allows the player to completely customize their character to their own specs. FFXI paved the way for it, but never really completely opened that door. The system isn't "perfect" at the moment, but it can easily be tweaked to awesome results. Even in it's current incarnation, I (and many others) enjoy it quite a lot more than having to chose a class and being forced to stick to it.
It makes finding activities to do in game quite a lot easier, soloing quite a lot more fun and varied, and grouping quite a lot more flexible.

Another innovation is the parity between crafting and adventuring, even here there's room for improvement (mostly in joint activities between crafters and adventurers), but there's a ton of potential for people that enjoy crafting and end up, in basically every other game, having to bear a ton of time/money sinking only for the future perspective of getting "rich" or at least economically independent.
Crafting in FFXIV is not a "sink", but it's part of the experience, designed to enrich it, and not just to be a "utility" service.

There's more, but work calls. I'm sure others will continue where I left if your interest is genuine.

***, I'm still trying to wrap my head around what people mean when they say stuff needs to be "fixed" in the game, and then never really elaborate on anything objective other than "wah wah no AH wah wah wah".

As far as I can tell, apart from issues with a laggy and unintuitive UI and repair system that was present back in September, the only thing this game really seems to need is more content, which is in the pipe, and to actually be finished, which it most certainly was not back in September.

I'm personally very afraid of what this supposed "battle system overhaul", which to my mind may be entirely unneeded, is going to entail. After how SP was neutered back in October/November, I don't know what to think about it.