The sheer fucking hubris of it all. The unexamined and unjustified hype wave. The "influencers" peddling the damn thing with naked cynicism. The recycled maps that often just took the same assets and tilted them sideways. The laughably bad QA allowing almost anything to be put in the chat box.
The way it just... stopped being relevant.
That is all. 
I was in the New World beta and discovered that if you tried to fish in a town it would crash your nd people around you's clients.
I reported this, heard back nothing, and then forgot about the game.
In the next beta I tried the same thing and it still worked.
On the game release (I apparently pre-ordered on amazon when it was announced as a free to play game and they honored it) I tried it and it still worked.
I have no idea if it still works because I stopped playing after a week.