There is no need to come up with "local TLDs" like .vibe, .local, .test and so on -- there is already an industry convention! macOS and most Linux distros support subdomains of localhost, so <anything>.localhost works. You still need the reverse proxy to do the host->port mapping, but you save yourself local DNS fiddling.
> There is no need to come up with "local TLDs" like .vibe, .local, .test and so on -- there is already an industry convention! macOS and most Linux distros support subdomains of localhost, so <anything>.localhost works.
That would work if your goal was to route traffic to localhost.
What if it isn't?
There are reasons why the likes of example.com exists.