We can either bury our heads in the sand, have a false sense of security behind CGNAT connections and keeping devices running without a firewall, commercialize IPv4 as much as possible to point of consuming loopback address spaces and make everything worse than it already is.
Or, we can move to IPv6. Yes, it might be painful for some people when they get their IoT devices hacked but at least it should spur change and make people realize that they can't just buy a toaster and connect it to the Internet.
Any decent router with IPv6 support sets up stateful v6 firewall rules blocking incoming connections and only allowing outgoing from your v6 subnet. Same as always like you say and most consumers won’t even notice a difference other than increased throughout.
Or, we can move to IPv6. Yes, it might be painful for some people when they get their IoT devices hacked but at least it should spur change and make people realize that they can't just buy a toaster and connect it to the Internet.