+1 for use-package being the only thing that's missing. I'm delighted at how nice this guy makes Emacs look and work with only built-ins (ido in Emacs 27, and fido-veritcal in Emacs 28 go a long way to increasing Emacs' ergonomics imo) but since they're reaching for some installed packages, might as well throw use-package in there to foster further growth.

(If I'm not mistaken, use-package almost made it into upstream Emacs, but they're blocked because one company won't give away the copyright for one contributor to use-package to enable it to be added to Emacs. For the larger Emacs community, I hope that happens soon!)