What I find curious is the (compared to pretty much every other MMO I've played) relatively high amount of players who come unprepared but don't mention that they're unprepared.
If you're new to a dungeon/ trial and have absolutely no clue what to do here... why not say so?
Why not write a simple "hey, first time here. any mechanics I need to pay attention to?".
I don't expect people to watch or read a thorough guide before every duty, though I welcome it if they do. Brownie points for coming prepared!
But at least tell others that you have no idea what to expect. That's common curtesy and has nothing to do with elitism. There's always someone who knows his stuff and can help, but silently hoping nobody notices that you don't know what to do is imo really thoughtless.
Even below 50 there are a couple of dungeons with mechanics that can cause wipe after wipe if ignored, like Qarn 1st boss, Chimera's skills in Cutter's Cry, Fruits in AV etc.
Yet when I wiped with a group and asked "hey, XY, do you know about the mechanics here?" I often get no response at all and quick explanations are being ignored. Just got out of another trial with people like that. Shiva really isn't terribly complicated. Lots of people watching cutscene, lots of early 50ish people. Asked "anybody here doesn't know what to do?

". No response.
Followed by four wipes because people died from standing in stuff, getting frozen etc, but ignored the offer from a RDM and me to lead them to safe spots aswell as the quick overview we gave.
5 people obviously didn't know a thing about this fight (which is fine) but didn't speak up (which is NOT fine).
The party chat is there for a reason.
I've met these kinds of people in every MMO but never to the extend as in FFXIV.