I agree Endgame content is not nearly as robust as WoW or other MMO's, but unfortunately the FFXIV design philosophy does not compensate for the mind set that "The game starts at Endgame." One has to look at the fact that these developers have a large internal data collection on what players do and what feedback they are taking from. Square is more likely to respond to feedback from its eastern audience rather than its western audience.

Before Shadowbringers came out Yoshi P. did interviews all over the world during the media tour. A common question that came up from Western interviewers was about a Mythic+ like system for potential endgame. Short answer: "They encourage people to take breaks." The impression that the interviews got regarding it was that Yoshi P. just simply doesn't want to do it.

Great video about how the Media tour interviews questoins
https://www.youtube.com/watch?v=sjMEzFhICPU