I would argue that the fatal flaw of this idea is that it is an online app. If this was solvable with technology, Meetup.com has a 15 year head start on you and they didn't solve it.

I think technology is antithetical to the goal you are working toward. Instead, start a local group and have a "all cellphones go here" basket when members enter so that when they are there, they are fully engaged and not doom scrolling the entire time.