It's interesting to see these dungeons as essentially a playable form of the Villainous Infodump Monologue. It's a bit disappointing that they've gone to the well three times, but I think it works fairly well in terms of merging storytelling and gameplay.

I think the Lunar Subterrane does it best, in part because there's actual sort of 'mechanical' reason it's happening (it's Real Golbez's crystal acting up), and partly because it actually does have a physical presence outside of the vision so we did actually Do A Thing, but also because it's much more sparing about narration. The bad part of endgame dungeons being like this isn't that they're visions, it's that they're going to be a near-daily experience for a lot of players, and when that experience involves a very rote speech then it starts to get tedious. It's like if Gaius' monologue played during his boss fight.