Imagine going back to the 80s and 90s and telling people "the web isn't peer to peer! We have to replace it!"
It would be extremely confusing. Didn't we invent HTTP and IP and the web to let computers shoot messages to each other directly? What happened to that?
There are many people advocating to keep using network address translation, refusing to let go of this workaround for a problem that IPv6 solved long ago.
Inevitably they either think that NAT == firewall, or that carrier-grade NAT is needed for their privacy. (I mentally translate that last word to "illegal activity".)
Because the whole point of NAT is that there are multiple machines behind it, so if you spin up a local web server on port 443 or whatever, by default it'll be invisible to the internet. Not just firewalled off, but not even on a routable address.
Most NATs do allow a hole to be punched, but it's a manual step that most users aren't even aware is an option. The process is unique to each model of NAT device, and there are hundreds if not thousands.
Because of address sharing, there can be only one port 80 or one port 443 per NAT. Of course, SNI and similar technologies can work around this, but this is also a relatively high hurdle to get over.
This is difficult enough at home, but in corporate environments it's no longer doable at all. Gone are the days of some early adopter running a webserver on a box under his desk for a decade! I mean, you can, but between the firewalls and the NAT(s) in the way, there is little chance it'll be accessible even internally, let alone externally.
There are other issues also: For technical reasons typical ISPs provide much more downstream bandwidth than upstream bandwidth. Residential-grade connection public IP addresses change semi regularly. Some ISPs are now so low on IP addresses that there is second layer of carrier-grade NAT in front of your home WiFi NAT. Home users have no chance of defending against even a DoS attack, let alone a DDoS attack, which would then also take out their personal Internet, not just their web site. Most people run Windows at home, which would be fine except that the consumer editions limit IIS connections to 10 concurrent requests. Etc...
Meanwhile professional, centralised web hosting can be had for $5/month, little more than a cup of coffee.
You could have a retort for every point, but fundamentally self-hosting makes no sense. For example, you could say that people should just use a separate machine running Linux instead of Windows to host their site. Okay... what's the cheapest decent turnkey machine you can buy? $200? That's the same cost as 40 months of hosting on a cheap provider, and you still have to worry about your dynamic public IP, NAT punching, certificate management, HTTP security headers, NGINX configuration, etc...
It would be extremely confusing. Didn't we invent HTTP and IP and the web to let computers shoot messages to each other directly? What happened to that?