The concept of an IPv4 NAT router exists today because people in the '90s wanted to connect multiple devices without permission from their ISP. SLAAC lets you

The concept of an IPv4 NAT router exists today because people in the '90s wanted to connect multiple devices without permission from their ISP. SLAAC lets you extend a network without permission using ND Proxy, whereas DHCPv6 IA_NA can only be extended using NAT. So I think SLAAC is good because ND Proxy is less evil than NAT.