It’s really hard to care about people who consider waiting for a webpage to build, a browser to load and a search to be typed as an acceptable solution to documentation access.
Web documentation is easy to produce and is acceptable to many. All other kinds of documentation can also be converted into web documentation, therefore you do not have to spend extra effort for it.
Terminal documentation is more difficult due to the limitations of displaying things in the terminal, therefore it requires more effort.
I certainly agree that those who prefer terminals are a subset of developers - despite this missing the point of terminal-friendly documentation also means generally reusable and integration friendly, unlike a full web application - but terminal documentation is objectively orders of magnitude less work than writing web app for showing documentation.
Terminal documentation just means plan text. You print it, that’s it. Making it pretty involves indents and line wrapping. Any source formatting is just ignored.
Plus, while one can dump plain text to HTML files it's still easier to just print the text.
Text based interfaces and terminal applications came first exactly because they are simpler than web browsers and applications.
We're not talking about a "TUI" app here - a terminal doc tool just dumps plaintext and terminates.
Rust takes forever to build too if you've never built the project before, but most people also build that ahead of time too. Repeated doc usage and repeated builds/checks don't require the "full build"