End game problems in FFXIV largely boil down to gut decisions made by the developers ages ago that just ended up making the entire thing worse.

1) Making it so that top end content requires a specific group composition based on category of role rather than the actual role. Thus, shield healers, pure healers, melee dps, ranged dps, magic dps, and tanks are the FFXIV roles rather than healers, tanks, and DPS. This is implicitly enforced by the bonus system so if someone wants to be cheeky, they can say "sure you can go four melee dps", but you'll never see anyone do it.

2) Having lockouts based on group rather than the character. It should be a character lockout and per job so it is possible to run savage on more than just a Tuesday. The fact they had to add an option for "rewards unclaimed" is kind of silly.

3) The change to make the final book convert into other books sort of pushed out mid to late season prog in PF outside of a static. A good analogy to the scenario is printing money and sending it out as aid to give short term relief, but then having inflation occur making things less affordable later. Because it lets people get gear faster in savage, people soon don't want to run those fights anymore since they have no benefit and only do them to get to the last one, and it isn't like those people are going to go help others trying to clear earlier fights if they need to reach m4s with the herd that includes most of the competent healers and tanks.