> I think it still belongs between the internet and most networks made entirely of desktop, IoT & personal devices.

I think your belief has been shaped by the fact that adoption of P2P protocols was hampered by NAT for over a decade, and that developers often write software that trusts the local network. Default deny policies help protect insecure servers for the time being, but I'd like to see servers that utilize encryption and authentication instead of relying on simple allow all/disallow all firewall policies at the connection level.