I’m of two minds here.
These are player created requirements that are unrealistic.
I had KSM all 3 seasons, AOTC all 3 as well as some mythic kills, and still struggled to get into heroic CN or a M+15. One-shotted CN when I finally got in (most bosses) and the 16 key went over by 5 minutes, but it was the first time for most of us in the group in Grimrail Depot. Full 278 gear on my toon. BM hunter (so lust utility, traps, etc.). It “should” have been enough.
That being said - the game encourages you to make ridiculous groups.
No one wants to have their key depleted. Especially early in the season (prior to current KSM) when it is harder to get invited to pugs.
No one wants to waste time redoing bosses that are 5-12 minutes long after a wipe… and that’s not counting rebuffing, running back, refilling leavers who are impatient, etc.
The game actively pushes you to just overgear/overpower content - because it punishes you if you don’t.
So it isn’t an LFG tool problem per say, nor is it a player problem exclusively. It is a combination of things.