You know, I had an idea 20 years ago for ghost races like in Super Mario Kart but applied to Diablo. I still think it would be a great idea. The concept is players could record their best runs in a dungeon and share them among friends or the public. You'd then enter the dungeon and a shimmering white ghost of the recorded player would be going along doing their run and you'd try to keep up if you can. The ENTIRE POINT would be to help give the COMMUNITY things to do, to socialize, you'd have to generally TALK to people and say "hey, wanna race my ghost time?" This BUILDS the community, gets people talking, sharing, being interactive. I'd implement a method of people watching others try the run in observer mode, with a chat enabled so people can comment.
And so they actually kinda implement this system with Challenge rifts, but in the MOST ANTISOCIAL way possible. They just basically make it a queue like an automated match maker. Here, try to beat someone's time. You get 1 per week randomized. So it takes ANY SENSE of talking, communicating, building friendship, and just strips it out of the concept.
Oh, Blizzard....