What I found hylarious is that due to the existance of a LFD feature, nobody speaks in groups, there is little to zero chance to make friends unless you accept one of the dozen spam guild invites and get lucky right away.
Is this proof enough that modern WoW killed community in the name of convenience or not?
I don't think it is solely LFD. I think there are other factors that contribute more to the lack of communication in groups.
1: Content is much easier. You no longer have to stop before hard pulls and work out a strat or CC order. There isn't any reason to really discuss any trash pull or boss in a dungeon. After you have done a dungeon and read a boss journal you basically just zone into a dungeon and AOE everything until the boss fights. The boss fights while more complex just are not that hard. Rattlegore from vanilla is probably a more hardcore dungeon boss fight than anything in WoD.
2: You are always doing something. Due to nature of most classes and their rotations you are constantly busy. Unless you are in vent there is just not really much time to shoot the shit.
3. No downtime.
Rushing through a dungeon while finger blasting your rotation and never needing to stop has made it so you will never need or even have the time for casual chat. Every single time I go back and play EQ (P99 or Phin) I have always had at least 9 or 10 people on my friends list by level 10. Classic EQ content is not really difficult and there have definitely been times where the only group chat has been "INC ****" for an hour but longer encounters, less key spam and having to sit on your ass helps facilitate casual conversation.
LFD came in at a time when dungeon content was already a joke. The heroic dungeons at the release of Cata had some difficulty and there was more at least strategic talk before some pulls and some occurrences of downtime that allowed you to shoot the shit even if it was only for a minute. After they nerfed the dungeons it went back wrath levels of not giving a shit about who was in your group and stayed there. The only conversations that happened in wrath before LFD were the initial "LFG/LFM", once you got in the group that was pretty much the end of chat until the "gg" at the end or drama related shit because someone rolled NEED or fucked up.
The only thing LFD really did was remove LFG and LFM spam from general and city chat.
I will say that *cross server* LFD was a mistake though as it took away some realm identity and the initial implementation of it in terms of finding cross-realm friends and playing with them again was pretty much shit. The idea of directly teleporting to the dungeon is also something I struggle with. On one hand I liked the experience of having to run to the dungeon and the random pvp encounters that crossing through enemy/contested territory would bring up but on the other I also remember how annoying it was after doing it a dozen of times. If the system had existed from the very beginning and was kept server specific I don't think Vanilla, TBC, and most of Wrath would have went any differently.