Depends on how you use/play it, just like it depends on how you use social media or TV. A lot of my social media usage is finding stuff and sharing with friends in group chats and us having discussions/laughs over them. Most of the "TV" (streaming services, anime, etc) that I watch is done with my partner or a group of friends. If you just turn your brain off and grind, then WoW or any other MMORPG is an equivalent mindless time waste to just consuming TV. I suspect it gets more fondness in nerdy circles just because more folks in these circles relate to it.
I didn't play very long (under a year) but I had a ton of fun mostly thanks to my guildmates. I didn't mind some grinding, and WoW has plenty, but most of what kept me coming back was to meet up with other players I had gotten to know and had a lot of fun playing and chatting with.
Definitely, and I have many friends who still play MMOs as adults who do the same thing. They open group chats with longtime (and new!) friends and play. The grind is a thing to do while everyone hangs out. But I also know people who turn their brain off and grind as a way to just pass the time. One of my favorite ways to waste time is to get a little high, fire up Diablo, and grind away. It's the same with social media. Social media can be social or it can be parasocial depending on how you use it.
