I've noticed in quite a few cases where NPCs give very confusing dialog, but since this doesn't appear to be specifically a language issue I am posting this here vs the feedback section per the sticky under localization.
A few days ago, for example, there was an issue of "Lootblox" talking to the player like they had an item they didn't have (and couldn't obtain if they never did before) which distracts the player from understanding how to get the key item they were selling. I wasn't the first one to be confused by this.
More recently I was stuck for an hour trying to figure out how to complete a nation mission for rank 10 because I had no idea where to go to complete it after sorting my inventory. My confusion there was stemmed from the fact that some NPCs actually talked like I was already rank 10 after getting the rank 10 animation, and I was even able to get a Trust I can only get at rank 10, but other NPCs talked like I was still doing the mission. I eventually had to figure out to interact with a nameless point to complete it and the issue here is that literally nothing in the game would clue a player into that fact. This gets excused by players to read the Wiki, but since when is it good game design to expect a player to read a Wiki to do anything? I for one prefer to immerse myself in the story and try to figure things out, but broken NPC interactions in cases like this break immersion. The message "Come back after sorting your inventory" just isn't meaningful and that remains a problem. And when NPCs act like something is already completed when it isn't that just makes it more confusing.
Now, don't get me wrong: I don't think that that game should hold my hand. I absolutely do NOT want to play FFXIV for reasons like the hand holding, but at the same time I do expect NPC interactions to at least be intelligble and reflect where the player actually is in the game. When you are unable to complete a mission due to a full inventory the game should clearly tell the player what they should do to complete it and the NPCs shouldn't act like it's completed if it isn't and the mission log should be updated to reflect this. And when an NPC has information for the player it should be able to detect via flags if that information is appropriate to give them.
I hope this feedback doesn't create a slippery slope though. I feel that making the game too easy is what let to the current era of inactivity. It took me 5 years to get to level 75, but now that people can do that in a month there's no real reason for most to stick around except to complete the stuff they couldn't do before, and since the game is more or less dead in terms of cooperative play (we have to use trusts to do what we used to do together) there's all the more reason for the game to have clarity since it's not like I can just ask something in game to help me.