I think it does more harm than good.
Matching urls in code is just a little bit harder.
Servers are capible of running more than one port on an IP and usually different services don't conflict.
Add a subdomain if you need another service running on a different IP.
This practice make configuring things like wordpress, SEO, and cloudfare just a little more complicated.
Here's an idea. If someone contacts your server at the ip listed for that base domain on port 80.. just serve the page. We don't need to give the server any more clarification.
The nowww side argued that the www is antiquated and no longer needed since practically all http links would go to the www.
The yeswww side was more focused on other services like mail or ftp or whatever which might have a port 80 endpoint as well.
In the end no one actually cared and port 80 and 443 forward to the main web site as the www counterparts do.