Least worst option? Treaties between national governments.
Whether it is ICANN or FIFA or your local electric cooperative, self-replacing boards will corrupt to the limit of their power. Elective governments have at least SOME accountability.
Handling IP-compatibility (and DNS) as a matter of national sovereignty is the only sane position to take. The fact that we have a unified authority is a throwback to ARPANet. Convenient? Certainly. Survive a dustup between major powers? Don't make me laugh.