Except the NAT device will stonewall traffic on every port except the ones I open, for my entire network, and then I can just worry about securing the software listening on those few ports, instead of having to worry about the firewalls on every device I own.
Tldr default nat behavior is a state full firewall.
Yes, thank you for repeating what I just said, and justifying my desire for a nat. I do infact actually know a few things about computer networks and tcp/ip since I spent 7 years writing software to interface with and monitor them.