The weak points FFXIV has are mostly with side content and repetitious content needed to grind out levels of other jobs, as well as the hardest content. So the core of the game is good, but that core only lasts so long and then people are stuck with the dregs.

The dregs of FFXIV are...

1) Savage
2) Hunts
4) Relic
5) Crafting and Gathering

The core of FFXIV is the same as any RPG: You fight things, go up in level, find ways to get money to buy better gear or just get better gear from dungeons, until someone completes the story or whatever it is for the current patch and expansion. Then there are the 8 man and 24 man raids, trials, etc that are around at end game to keep people busy (This includes EX).

The dregs are basically the vestigial content that gets bolted onto the main set of content that only some subset of the community gets involved with, or ends up being monopolized by a specific group of people. Since they aren't really considered core to the game they get released and then people are told to go have at it.

1) The Hunts Problem -> The hunts are an example of overworld content that gets monopolized. Effectively, people grouped together to form hunt trains to take down the hunts efficiently due to the increase in HP pool, which sounds great except that so many people end up going on these hunt trains thanks to DC travel, people can't even zone into the areas right away. Not to mention if someone is on a console they are at a disadvantage here because the load times are longer for them. Hunts can die in as little as 15 seconds after engagement, and that is the current hunts. Older hunts can die so quick on some nights that there has to be a wait period of about 5-10 seconds before pull, or too many people would just miss out.

2) Crafting and Gathering -> This is one of those things where its not really fun to do it, but you do it anyway because its needed for unlocking certain beast tribes, melding materia, and repairing your own gear. The system for crafting was supposed to make it interesting, but like all repetitive tasks that you end up having to do a lot of, the extra steps just make it tedious. People invented macros for crafting for a reason.

3) Savage -> The problem with savage is mostly they can never be consistent in designing the content and setting difficulty with it. That and the fact the fights get designed for specifically a set of roles means if you are playing the popular job, you're going to have a hell of a time trying to do savage as you compete with all the other Jims and Johns playing that same popular class. Meanwhile, the guy who decided to grit his teeth and play something repetitive and old has no trouble finding groups even if he is mediocre (Or you played a healer this expansion and survived the apocalypse known as Abyssos Tier)

4) Relic -> Its one of those things that either gets tied to something that is too repetitive, or comes in after the glory is over with the content it is attached to and then people feel the same burn as if it was attached to something repetitive. At least in Endwalker we just run around shooting hunts all day... unless you never did the Manderville quests. In that case, strap your butt in because you got some questing to do that will take you a good while.