It's like `python3 -m http.server` but in a language that is rarely pre-installed on systems with an external program that has two external dependencies.
Joking aside, you are correct. Go shipping pre-installed is a yet to be seen nice-to-have on most systems.
That said, HTTP/2 support might be nice to have in Python's http.server or Node's http-server. Albeit you probably shouldn't use http.server nor http-server for production purposes, so it isn't essential.