Sure this is a nice and concise (yet somewhat trite) example, but this can be done easily with 1 line in sudoers as well (and is usually configured like this by default anyway).

Not that doas isn't great, but this particular reason isn't that compelling (to me).

That's the entire configuration. It does not need documentation that starts with a quick introduction to EBNF, the whole thing it's about as simple as you could possibly make it. Granted, if you're just doing small edits to existing sudo config it might not matter too much, but I find it appealing to be able to read and understand the entire configuration file and add new configuration easily.