It's true the higher level dungeons get outdated so much quicker, which is why I wish they would add them to the overworld in some way. Maybe just a part of the dungeon that connects to the world that you can zone into and do stuff in, maybe add new gathering points and new treasure maps that bring you inside them. It's just a shame that the areas get wasted like that. Sure, people still run them, but eventually they'll disappear from rotation. I know it wouldn't happen but it's fun to dream