As an endgame FFXI player until just a few months ago, this isn't surprising to me, with Voracious Resurgence ending in May.
It is a shame though. There was a huge resurgence in players leading up to the 20th anniversary, people who really wanted XI to continue. But the development team put the writing on the wall when they said there would be no new outdoor zones being added for Voracious. That took a lot of wind out of the playerbase's sails. Basically all people wanted was another Reisenjima (the endgame zone added for Rhapsodies).
That's basically why I quit. Just seemed like a dead end. That, and the instanced content introduced over the past few years (Odyssey and Sortie) introduced massive power creep, with equipment that trivialized all other content in the game, creating a feedback loop of doing Ody/Sortie to do more Ody/Sortie. Bearing in mind, these are 30min-1hr activities you can only do once a day, and are strictly 6-man so that caused a lot of awkward exclusions among friends.
The EXP required for the Master Level system they added also got severely out of hand, with ML35-50 requiring such vast sums that it all but required botting overnight. No avenue for real parties to grind it in a sane amount of time. (Well, there was an AoE method for real parties to EXP quickly, but they nerfed it of course.)
All this is to say, endgame quickly became very stale with these new additions, and with no light at the end of the tunnel as far as real new content.
Personally, I think they should've just rolled all the MMO subs into a single and simple monthly fee that gave you access to all 3 MMO. I think the thought of paying for 2 MMOs scares people and there were people who legitimately wanted to try FFXI but the price for such an old game turned them away.
From what I remember, this presented difficulties because something about FFXI's subscription is baked into PlayOnline.
Real talk, but SE desperately needed to a Realm Reborn style overhaul of FFXI years ago. Not necessarily graphically (it's aged shockingly well with some HD mods), but tear out PlayOnline completely, and rebuild the game's foundation so it isn't based on and limited by 20-year-old PS2 devkits.
Those are the fundamental issues that plague the game, which prevent it from being added to or modernized. Just so much antiquated garbage code that no one on the team is qualified to touch without breaking something. POL alone has deterred how many countless people from playing XI?
