The best thing about SLAAC is that it forces your ISP to give you at least 64 bits. Otherwise you know Comcast would only give out a /128 and charge you for more, so you'd use NAT at home just like IPv4.
Some ISPs are reportedly giving out a /128, and SLAAC works adequately with a router performing IPv6 NAT, so those ISPs don't see a problem.
Mobile phone as WiFi access point is another common way people access the net nowadays. I've occasionally seen permanent installations, with a phone taped to a window. I've never seen a mobile phone AP offer IPv6 to clients, but if they do they have to use SLAAC-compatible IPv6 NAT in that situation.
Wow, that’s diabolical. Presumably these routers are some custom CPEs then? I don’t even know whether regular home routers support NAT66.
> I've never seen a mobile phone AP offer IPv6 to clients
I’ve only even seen it work without NAT when there was any v6! Usually the phone gets a /64, and there is a bit of trickery involved to make that shareable to other devices (NDP rewriting), but it works pretty well.
iPhone does that, and I’m pretty sure I’ve seen Android doing the same. The phone keeps a single /128 from the /64 assigned by the mobile network on its mobile interface and the re-assigns the /64 on the WiFi interface. No NAT is involved.