Not really, they’d clash all the time. 8080 is the default port for a non-privileged webserver, that is, web server, something you put your own stuff on, not applications/daemons that happen to have a web interface. E.g. ComfyUI uses 8188 for its web interface, deluge 8112, neither will serve your index.html.
NixOS. Gentoo gets into trouble when you need multiple versions of the same library at the same time. Also while the infrastructure supports it it’s annoying that gentoo doesn’t provide pre-built binaries, like yes some people might want to have reason to build their own bash but I think I’ll be fine with a standard build. NixOS? If you install something usually it’s going to be pre-built. Change a couple of configuration flags? May or may not be pre-built. You want to apply a custom patch? It’s going to seamlessly build from source.