When a game like this makes as much money as it does off of cash shop outfits and fantasias, or people spend as much time as they do finding pieces and throwing outfits together in game, I don't think you can unironically say that aesthetics of a player character are not a major tentpole in a massively multiplayer online role-playing game like this one.
Even transmogrification in WoW is a big deal. Cataclysm was an expansion that was, in general, bleeding subscribers. WoW had only experienced growth prior to that time and it was the first time the game was ever on a downward trend. There was only one point during that expansion where that bleeding stopped and the subscriber count went back up. If you're trying to guess where this is going next and you guessed that it was the same patch that added transmogrification, then you'd be right. Their numbers have shown transmog to be a very big deal for players. A not insignificant amount of people spend a lot of time running content and putting together outfits that they can show off on their characters. And they've only added more systems since then to aid in that.
FFXIV is no different in this regard and to suggest it is is to woefully undersell just how important glamour is to a good deal of players. It's not anything that's going to solely prop the game up when other aspects of the game are caught lacking, but it's also not at all a minor part of it.