These kind of servers are useful for quickly serving a folder of files locally. Security isn't a primary concern for these kind of use cases.
$ npm install http-server
$ http-server .
$ go run github.com/eliben/static-server@latest
I have this seen also in automotive. "This is no problem, because this is not connected to the Internet." Then a few years later you have a DefCon presentation "GM hack, you can control the whole car via the Internet".