Whole model same as IPv4 (DHCP, NAT, ICMP, DNS, ...) just in v6. If IPv6 and IPv4 would be essentially the same from the get go, IPv4 would be a niche 20 years.
Sure everything above IPv6 have, but it took years and years of screaming to get it.
> Whole model same as IPv4 (DHCP, NAT, ICMP, DNS, ...) just in v6.
All of those things exist in IPv6.
And it is physically impossible for DNS to be the same, as you have to create new resource record types ("A" is hard-coded to 32-bits) to support the new longer addresses, and have all user-land code start asking for, using, and understanding the new record replies. Just like with IPv6. A lot of legacy code did not have room in data structures for multiple reply types: sure you'd get the "A" but unless you updated the code to get the "A7" address (for "IPv7" addresses) you could never get to the longer with address… just like IPv6 needed code updates to recognize AAAA, otherwise you were A-only.