You speak of Leavers having a sort of wealth that we lack and desperately need. What is that wealth (besides the obvious—the knack for living successfully for three million years)?
The knowledge that they’re surrounded by support (given by all to each because reciprocal support is needed from each); the knowledge that they’ll never have to go it alone with any problem—whether it’s illness, raising a child, or caring for a declining parent or spouse; the knowledge that they live under laws that have worked from time out of mind, that work for them instead of against them, and that protect rather than punish (and that for that reason are willingly embraced rather than constantly evaded, as in our society); the knowledge that when times are good, they’ll be good for everyone and that when times are bad they’ll be bad for everyone (this is what chiefly distinguishes tribal society from our hierarchical society); the knowledge that they have cradle-to-grave security—they have no jobs to lose and membership in the tribe is for life.
None of this comes about because tribal peoples are sweeter, kinder, nobler, or more altruistic than we are; this is just what works for people, and tribal society evolved as humans evolved, subject to natural selection (meaning that social organizations that didn’t work simply disappeared).
Note again that tribal society works well for people; it doesn’t work very well for products. Our society works perfectly for products but very poorly for people.