Another big benefit is ease of use setting up the Yubikey. My understanding is that these newer key types can be generated very easily using the ssh tools which already exist on your systems. Previously, it was very common to set up GPG keys and integrate them with SSH, which is not only more work but also fairly involved.

These new key types make it a lot easier to get up and running with storing your SSH key on your Yubikey. I would have used this format instead of GPG when I was setting up a Yubikey a month ago, but GitHub (and some other providers I use) didn’t support a new enough OpenSSH version.