Firewall team lead here. NAT forces the vast, overwhelming majority of connections to be unidirectional without any rules you need to maintain. Kills whole classes of attack for most people.

Looking at the impact to maintenance ratio, NAT is indeed the best firewall.

— Zimmie (@bob_zim) April 16, 2022

Exactly. And IPv6 took away NAT. Only low-IQ dipshit clowns repeat the absurd sentiment that “NAT isn’t a firewall.” NAT isn’t the only security you should have, but it stops 99.5% of attacks with doing nothing else.