I am not sure what you mean by "never mentions their existence", they are very clearly mentioned near the top of the git man page:
DESCRIPTION
Git is a fast, scalable, distributed revision control system with an
unusually rich command set that provides both high-level operations and
full access to internals.
See gittutorial(7) to get started, then see giteveryday(7) for a useful
minimum set of commands. The Git User's Manual[1] has a more in-depth
introduction.
After you mastered the basic concepts, you can come back to this page
to learn what commands Git offers. You can learn more about individual
Git commands with "git help command". gitcli(7) manual page gives you
an overview of the command-line command syntax.
