man comes from Unix, info comes from Emacs and maybe the OSes it was developed on. The GNU project also comes from that ecosystem, so even their drop-in replacements for the original Unix tools have info pages.
Specifically, info appears to come from ITS. Stallman hacked on ITS back in the day, and the first time I logged into an ITS system (http://up.dfupdate.se/, if you're curious) and used the online help system, I suddenly realized why GNU was always trying to foist this weird manpage alternative on us.
(I remember back when I first got into Linux, like early 2000s, it seemed like a lot of the core GNU man pages were just stubs that said "For documentation, use the info system". Luckily they seem to have backtracked on that?)
(I remember back when I first got into Linux, like early 2000s, it seemed like a lot of the core GNU man pages were just stubs that said "For documentation, use the info system". Luckily they seem to have backtracked on that?)