I'll admit XI wasn't perfect but thing like losing exp on death weren't really as bad as they sound.
Was it annoying to delevel and lose gear sure. But the reality was it was also easily avoidable just one or 2 extra kills in an exp party would buffer you nicely. And failing that just told your old gear for a bit till you got part way Into your level. (if you sold your old gear the second you dinged then sure you'd have issues but that's because doing that was a stupid thing to do)
I quite liked the loss of exp on death as it generally made you respect the world a lot more and generally care about your character. Ffxi was the stop look both ways before crossing the road kind of environment you had to respect the world around you. In comparison xiv is just step out In front of a great big truck because it just doesn't matter if it hits you.
Like many have said vanadiel is a much deeper world and is/was more alive than eorzea ever will be. And it did feel much grander as well. One of my first quests involved me climbing a hill in gustaberg to visit the memorial of the miners. In truth by the time I made it to the top I was maybe only 4 or 5 minutes away from bastok but it felt like I had gone so far. or even the first time I made it to the dunes.
The world was more dangerous but not stupidly so. People have said how even running to jeuno at low level was a nightmare but it wasn't. There was a clear path with sign posts all over the place and if you follow the path you would very very rarely run into any issues. If however you ran in a straight line across the zone then sure you'd run through lots of dangerous monsters that could easily kill you.
Community was better as well. And general player attitudes. Generally speaking in XI it wasn't about "I" it was about "WE" it was about making players stronger as a group and not so much as individuals.
My LS for example had 15-20 people that would come and do temenos even though they didn't need it. And then people like myself who never needed appolyon or einherjar but would always turn up to help. the goal was generally always make the group stronger as a whole. I think that's why I'm still friends with many of the people I played XI with even 7 years later.
I sometimes think that's a key thing. If playing XI you saw the game as all about "you you you" then you wouldn't really get very far at all and you would struggle to find parties or people willing to help. But If however you saw the game as "WE" or "US" then you would find invites for exp parties and things came very very quickly even as lol jobs and any help you needed was never far away..
I think that's part of the problem xiv community has. It's all about "me me me." And thats generally why so many groups and static and things fall apart or why so many people jump fcs or linlshells so frequently. Join a farm party get your drop and run for the hills. there's no loyalty or consideration for those around them. get what you need and jump to the next group.
If you acted like that in xi you'd find you'd never get an invite for anything at all ever. Yet in xiv it's entirely acceptable behaviour.
Someone also mentioned things like airships running on strict timetables in XI and vendors stock changing based on days of week and conquest standings or even waiting till the next day to finish a quest. Yet these things helped make vanadium feel even more alive. In essence in ffxi the game revolved around vanadiel. It was centre stage. The player was just one tiny part of that. And they had adapt to the world around them.
In ffxiv however the game revolves entirely around the player. The world adapts to the player. With all its instances and stuff going on for every little thing. And I think that is a big part of why eorzea will never be the living vibrant world vanadiel is or was..