That's the point, though. An SSH key gives authentication, not authorization. Generally a certificate is a key signed by some other mutually trusted authority, which SSH explicitly tried to avoid.
A rather niche use-case to promote certificate auth... I'd add the killer-app feature is not having to manage authorized_keys.
Not sure why you need to belittle one example just to add another
But what I found, empirically, is that a substantial number of observable SSH public keys are (re)used in way that allows a likely-unintended and unwanted determination of the owner's identities.
This consequence was likely not foreseen when SSH pubkey authentication was first developed 20-30 years ago. Certainly, the use and observability of a massive number of SSH keys on just a single servers (ssh git@github.com) wasn't foreseen.
See ssh_config and ssh-keygen man-pages...