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.