NAT and CGNAT break the basic idea of how the Internet was designed, forcing everyone into servers and consumers. We've just become used to it, and most people have never experienced it any other way.

The Internet was supposed to be a purely peer-to-peer network, where the addresses on each side of a connection pointed to an end node. That's why protocols like FTP or SIP break when NAT is used, and why you have to play games with port forwarding if you want to run services from your house (assuming you have a public IP address at all).

> You mean it's fixed by NAT and CGNAT. Because it's works just fine for me.

CGNAT works for you? Do you play video games at all? Because there are all sorts of people for which it doesn't.

The fact that you may be fortunate enough to get a publicly-accessible IPv4 address on your WAN interface does not mean everyone else is. This type of attitude seems to be akin to "I gots mine."

Until a service's WAF catches your /32 because your ISP had previously handed it out to a spammer.