If I could vote, I would do for an offline FFXI, maintaining every mechanics and content, just reducing the requirement for stuffs
The thing that makes XI special in the first place, that adds a spark of life to the game is that it's online. Even if you don't play with other people at all, the fact other people exist in the world adds unconscious value to it in your mind. This is why we are still playing it so many years later, if it was offline you think it would be great and you could play it anytime you want. In reality you would never login to it, because the spark of importance / life is now gone.
When you get a cool drop, wearing it matters because other people can see you with it on or you have the option to play with other people some day (even if you never do, the option is there). Even though you know it's a video game, the fact other people exist in the world increases the status of that game and puts it above something like Mario or Witcher 3. XI isn't just a game, it's a virtual world.
It's also not just that XI is online that makes it appealing to us, it's that it is populated with people from a certain era / mindset that we are from and so it feels nice to be in because we fit in with them. As opposed to going and playing Fortnite or some other modern audience game, where you don't fit in at all.
