I use it in particular for bash, mostly because it has better expositions for parameter expansions. To the point that I know searching for "%%" in particular will get me to the correct section.
For everything else… I think it's also necessary for GNU find expressions?
I use the online versions, e.g. https://www.gnu.org/software/make/manual/html_node/index.htm.... In this form they are pretty good documentation (although that is usually due to being comprehensive and adequately written, nothing really to do with info beyond supporting adequate structure).
I occasionally use gnu info. My favorite tool is pinfo which has a man mode that adds navigable links to cross references in man pages and can shell out to hyperlinks. I usually have that aliased as man.