Whenever I play modern WoW I'm always talking w/ people.. Mythic + keys require communication and people are always either in the in game voice chat or discord.. Same with raids and rated pvp. I even get a lot of banter when just running islands tbh.
I never touch normal/heroic dungeons or LFR though those are hot garbage. Timewalking is fucking miserable too if you're pugging. Last time I pugged a timewalking dungeon we were stuck on the first fucking trash pack for over 10 minutes because the dps wouldn't read chat and interrupt the healer I ended up dropping group mid fight and never timewalking again.
One of the problems with modern wow is that you have to put in dozens of hours to determine the appropriate difficulty level for your enjoyment and the user-base is segmented into much smaller groups of people due to that. Additionally, when designers offload the difficulty choice to players a lot of them aren't going to put up with having to slog though a dozen hours of non-enjoyable play to find something appropriate. It is entirely reasonable to complete some dungeons and assume that there isn't an entirely different form of gameplay hiding in that same space if you configure the options menu correctly.
It also reduces the incentives for that content to simply "a chance at more equipment". Some players are motivated by lore, exploration, etc. Someone motivated to do several Black Rock Depths runs in Vanilla to see progressively more of the dungeon before eventually finishing it is not going to be motivated in the same way to complete Normal, Heroic, Mythic, Mythic+ versions of the dungeon.
Finally, given the decade of precedence that each patch will bring with it a gear catch-up mechanism, fewer players than ever are motivated by equipment upgrades.