One thing to consider is that when IPv6 was invented, there wasn't nearly as big a userbase on IPv4 as there is now. At that time a clean-slate approach made mo

One thing to consider is that when IPv6 was invented, there wasn't nearly as big a userbase on IPv4 as there is now. At that time a clean-slate approach made more sense than it does now. But yes these days things are different. And not all its features imagined to be big have panned out that way (and to be fair, even IPv4 contains several features which are no longer in use).