> I don't know. It seems like the best way to make friends is to force people to do some other task next to each other a few days per week and let things form organically after they are around each other for a few years.
You need a “shared struggle” to build tribal bonds. Some kind of us vs it or us vs them narrative. A simple get together where everyone spends money and has a good time is never going to accomplish that.
That is why immigrant groups, religious groups, professional groups, etc are more resilient, and successive generations that experience more independence end up splintering and otherwise loosening the bonds.
See also hazing in militaries/sports teams/“Greek” organizations/etc (not that I condone hazing).
I don't really think that it has to be a struggle. For example if you started hobby A (which could be an easy thing) then you'd meet other people doing the hobby and could bond over your shared interest etc. But having said that, difficult things will always bond people faster and better, especially if it turns the dynamic into an us vs them situation.
I find that really outgoing people do great with any situation such as e.g. a dinner, but the truth is they do great because they don't need the shared interest. If we were kids and a really outgoing kid showed up they could just hang out with us without having the slightest interest in our games, simply because they were fun to be around.
Personally the kid analogy works quite well to help me understand the dynamics, and sadly what we lose as adults is the ability to walk up to any other person and go "oh is that an abc", and then just joining them AND to be accepted for having done so.