[alex_smart]

It wasn't replaced, the other two commands were added to the cli.

It will take decades before git checkout will actually get replaced by git switch/restore in all the git books, tutorials and search results. Most normal users will keep learning and using git checkout in the meanwhile.

I understand why they can't actually deprecate existing commands. The git command is used in far too many existing shell scripts across thousands of companies.

I would argue that this is actually a fundamental deficiency of the "unix way" of doing things, where the same command is meant to be used both by human beings and in automated workflows. Automated workflows require backwards compatibility. Humans need easy to use interfaces that don't allow them to easily shoot themselves in the foot. The same tool cannot serve both needs.