Let us queue with same people

[SannaR]

Based on understanding the game.
Other games achieve it because you can send tells outside of dungeons because either it all happens on one server or they are better connected than SE's physical servers are.

There also aren't necessarily the issues with story spoilers because, for example, WoW players don't care for story as much as content.

Nor are there necessarily different reasons for being in the dungeon in these other games. Roulettes exist to supply dungeons that people queue directly for. Again, if I am entering via Mentor Roulette, I don't care for another run or to "run the next dungeon". Some people won't even be high enough level to "run the next dungeon".
To do that, the party would need to convert into a cross-world party. They would also need access to Duty Finder, which they don't have because they are already in a duty. Part of their being is partially on their homeworld (sometimes in a party there simoultenously) and part of it is on the duty server (in a party on the duty server), which could create further headaches for SE to deal with.
Define next instance. Next instance for me is... nothing, because I am a mentor. Next instance for a sprout after Sastasha is Tam-tara (but they might not have access yet). Next instance for a person leveling up might be the exact same dungeon because they are leveling via farming the same dungeon. Next dungeon for someone farming a minion is the same dungeon.
You can literally queue for 5 in FFXIV.
Can just open Duty Finder and queue again after you finish.
What if the queue needs you then and there, while doing the other duty? You'd be griefing to make them wait. So it doesn't keep you in the queue.

Just to take this a step further what happens if someone completed an instance for the 1st time? Normally the game goes oh here now that you're out of there we'll teleport you to right outside of the place or back to the instanced zone you probably qued from, but now the game will be asked to load you into another encounter of some kind. We all know that in the past the game has had trouble loading people back into separate for everyone type instances by itself. At least back in Stormblood there was when it came to post Lakshmi where people had been sitting on or laying on top of things while waiting for their que to pop. Not to mention when would this continue with this party screen pop up? A lot of people dip out and que up for something right away and could already be in another instance all depending on what they qued for and as what. Then there is the rare time when exiting a dungeon for the 1st time the story tosses you right into a cutscene.