I think some of the FFXI vets here are remembering the game with extremely rose-colored glasses. Yes, FFXI is awesome, but it wasn't even a remotely accessible game, and really still isn't. Sure you can level like crazy, but good luck actually doing anything without consulting a wiki or two at every step. The game UI offers an absolute minimum of help, especially for older quests and missions. Almost every modern MMO nicety that exists is in direct reaction to games like FFXI (specifically EQ, but the two are very similar in this regard).

Similarly, no one ever talks about how impossible it was to actually get anything done back in the day. There was no reward for replaying old missions, so you could only get help if you happened to find a full party who needed it, had friends who were super nice, or (more likely) had friends who needed to get you through that mission so they could help you with the one they were stuck on. If you wiped on a boss and couldn't reraise the party, you'd have to start the whole dungeon over, so no one EVER tried to learn fights the hard way. Everyone would read and memorize the entire dungeon and boss from old strategies, and god forbid you wanted to veer at all from the established path. If you think the "go watch a video" culture of FFXIV is bad, it had nothing on FFXI.

So yeah, I highly recommend playing FFXI, but realize what you're getting into, and realize that the people evangelizing FFXI are the small few who had the resources to fully enjoy it back in the day. Games have become much friendlier in the interim because at some point someone realized "hey, we can make more money if the game is actually playable!"

/rant