It depends on the scale. If a company has a handfull of hosts I'd argue that deploying the full AAA and PKI systems to back cert auth is doing it wrong.
Traditional ssh-key auth is simple and reliable, it's not until you have a large, complex and diverse user base that you need something more. That's why the huge fang sites use it. Every org doesn't need to mimic fang.
I don't understand this obsession with enterprise-level security on home networks and hobby projects. If you think it's fun and educational to set up, then you're doing it for fun and education, not security. If you're doing it for security, you're basically setting up anti aircraft guns to do what a drone jammer could do with way less resources spent.
I'm using SSH certificates to manage a few nodes in my homelab and it's a pleasure to not have to deal with managing the known_hosts file on my clients and authorized_keys file on my servers. There's only 1 line in my known_hosts for my nodes and authorized_keys doesn't even exist on any of my servers. If I add a new node to my homelab, I don't have to make any changes in known_hosts or authorized_keys in the existing nodes and it's easy to bootstrap the same known_hosts and sshd_config that I use everywhere in the new node.
SSH keys would make managing these few nodes a lot more complex that it is.
You really don't need to be anywhere close to mega-scale to benefit from SSH certificates and integrated authentication flows, though. Even at the scale of "only" 10 people with SSH access, the whole system can be massively simplified and made more secure by integrating centralized logins, and SSH certificates are rather perfect for this.
I implemented my own SSH certificate authority myself more or less, and while it's overkill for my own homelab-level stuff, I absolutely would never use anything else once I have more than like, 5 people logging into some set of machines. The benefits of centralized SSH access control that you can freely integrate (and pretty easily too, thanks to OpenSSH!) with your existing identity provider is really nice.
Traditional ssh-key auth is simple and reliable, it's not until you have a large, complex and diverse user base that you need something more. That's why the huge fang sites use it. Every org doesn't need to mimic fang.