Yes. Default-deny-inbound firewalls are much better than NAT because they are meant to provide security, can be managed (the "default"), and don't prevent deplo

Yes. Default-deny-inbound firewalls are much better than NAT because they are meant to provide security, can be managed (the "default"), and don't prevent deployment of new protocols. Also we might have a standard way to manage the firewall policy in this alternative future (upnp was done outside the IETF, and is a tire fire, because IETF rejected NAT). But also the whole posture of a home network and consumer os might have been different without NAT, maybe the host based firewall would have won out, who knows. In the alternative universes we can't assume other things remain the same.