NAT64? No what we needed was NAT66, and it took over a decade after IPv4 to deliver this. Because the IPv6 advocates were too opinionated on exactly how IPv6 should work. And since when has the world even agreed to anything even remotely complicated without trying to change things up?
You can do that with the privacy extensions. Plus on IPv6 you should get enough address space that it makes no sense to run a scan against anyone.
On IPv4 or NAT there's just 65535 ports to check. On a /48 with privacy extensions there's 2^80 addresses to go through, which from an external point of view don't remain constant. You can't even ping all of that.
As a end user, my inbound ports are all closed, and I don't care about scanning. But I don't see why everyone should be able to differentiate traffic from my phone from traffic from my laptop so I'm happy that they use the same public IP to connect outside.
Have you ever heard of TCP/IP stack fingerprinting? It is very likely that someone intercepting your traffic can tell apart your phone and your laptop regardless of the originating IP address. Odds are they can even tell your operating systems.
It's not because someone can say whether I'm at home or not by looking at the lights that putting a plate in front of my home saying whether I'm here or not is a good idea ^^ (sorry for the poor metaphor;) )
It's more like that plate is already installed, fully listing the occupants and whether they are home or not, and you are objecting to putting on the lights since people on the street might see you're home.
Anyone who can either man-in-the-middle your traffic or is the intended recipient will be able to do fingerprinting based on your TCP/IP traffic. In addition, a lot of your traffic will likely be HTTP(S), in which case the recipient servers will also be able to set cookies, and perform various additional forms of fingerprinting to learn even more about you. The idea that hiding behind a single IP address gives you any protection is delusional.
