FYI - the Emacs binary that's bundled with pre-Catalina versions of macOS (as /usr/bin/emacs) is 22.1, which is an ancient version from 2007. Apple kept that version because it's the last one that was released as GPLv2, and they've avoided bundling anything that's licensed GPLv3. This is the same reason that macOS includes an ancient version of Bash, and why they're switching to zsh as the default login shell.
Because it's so old, no one bothers to maintain compatibility with it anymore, and almost all modern elisp will break in some way if it's loaded in 22.1. Somewhat fortunately, it seems like Apple has removed this emacs binary from Catalina, so it won't be an issue on future versions of macOS.
To get a modern Emacs: https://emacsformacosx.com/ has binary builds of the official Emacs releases, with some additional scripts that let you launch it from Launchpad, etc.
Because it's so old, no one bothers to maintain compatibility with it anymore, and almost all modern elisp will break in some way if it's loaded in 22.1. Somewhat fortunately, it seems like Apple has removed this emacs binary from Catalina, so it won't be an issue on future versions of macOS.
To get a modern Emacs: https://emacsformacosx.com/ has binary builds of the official Emacs releases, with some additional scripts that let you launch it from Launchpad, etc.