Historical difference in style and preferences. GNU’s Not UNIX and all that Jazz, so they have different conventions, some of which would not translate to a man page that well. Plus Texinfo is a tool for generating multiple output formats from a single source.
Typically (unless this changed at some point) the info pages are the canonical reference for GNU projects and the man pages are to accommodate Unix hackers.[1]
Typically (unless this changed at some point) the info pages are the canonical reference for GNU projects and the man pages are to accommodate Unix hackers.[1]
[1] https://www.gnu.org/prep/standards/standards.html#Man-Pages