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).
