I've often wanted something of a service that produces something similar: creating groups of people that commit to spending time together on some task or activity. E.g. people who are into sports commit to meet up N times to go watch their local team, or people who love animals can volunteer at an animal shelter weekly for a couple of months.
The 'tech' part of this probably comes from: 1) matching people well to groups, like considering age, personality, politics, location, interests, etc to try to create a good fit. and 2) making it much easier for them to participate in activities, like by automatically booking tickets for events, etc.
Obviously there would be challenges. How do you prevent people from flaking or bailing? How do you handle groups where one person is clearly a bad apple?
I totally get that not everybody is like that, but I am, and so I stopped going to Facebook.
These days I'm in private Whatsapp groups for my direct family and so I learn about what they do, and not the random stuff that my neighbors and 20-years-past classmates did.
My wife is still active on Facebook and I actually do still visit occasionally to boost her posts but that's about it.
Over the next five years though, content gradually shifted to mainly image crafting. Over-processed photos, highlight reel curated trip photos, major life updates, etc. It felt like the bar was higher on what people would share, but unfortunately that removed a lot of the things that made FB fun in the first place.
I don't know whether it was a more universal shift or whether it had more to do with the age of my peers.