Anyway, cligen needs just 1..2 lines of code (`import cligen; dispatch fun`) to infer & generate all that from a pre-existing proc/func. Very low ceremony. `clap` & `argh` have more intricate specification/convention languages to learn, like most arg parsing / dispatching tookits.
CLI tools are a diverse lot. What help text similarity exists largely flows from toolkits or their defaults. E.g., Rust `argh` output differs (at least on their home page) from Rust `clap` in showing default values. So, your own 2 reference points already disagree on that default, at least in their examples (likely all 3 can say "whatever" with work).
This diversity is one reason why inflammatory rhetoric like "wins" or "good decisions" for ultimately context-specific (&tough!) judgement/aesthetic calls about defaults is unhelpful. There may be a little "back pressure" from users and from completion systems like Zsh's - but if you look into Zsh compctl you will see dizzying diversity of CL syntax & help formatting. The cligen defaults at least let you use _gnu_generic (as can both `clap` & Rust `argh`, I'd guess).
There are various reasons for all that diversity. Users after running -?/-h/--help/etc. do prioritize "the information" (for some value of that) over the formatting, as with most documentation. The diversity is also not going anywhere, as evidenced already by Rust `clap` & `argh` discrepancies. Devs just like different things. The docopt people like to start closer to free-form text (but do have a help parsability requirement).
I did not expect you to be aware of bu/ tools. I just thought you might be interested in CLI tools outside a standard repetitive bubble. Most people don't seem to like CLI tools like you & I do.
Using Rust in firefox was likely the most persuasive app for "can be used for real things", as has been mentioned (by almost everyone). I kinda doubt `clap` (inspired much of | saved much dev time for) `rg/ripgrep`, `exa`, `fd`, or whatever, for example (though it probably did help for greater uniformity).
