Automatic address assignment: Useless. DHCP is better.
No more NAT: Useless. NAT is part of firewalls which are still needed. It's easy, and incredibly flexible.
Better multicast routing: Useless. Multicast is dead, and will remain so.
Simplified routing: Useless. This has been implemented outside IP
QOS: Useless. The IPv6 implementation is wrong for how QOS is used now.
Larger Address Space: The only useful feature in IPv6, but it was done wrong, and should be abandoned.
We need IPv8 that does things right for the internet we have *today* not the internet we thought we'd need in 1998.