what's wrong with public key auth as root? The "alternative" would be making a sudo-enabled login account. Another indirection, and probably not fully transparent...
Also far better to encourage running sudo for every command, gives a nice simple audit log of what happened, right there in your syslog, so you can identify and undo mistakes, and also eliminate lines of enquiry.
Clearly you can cover your tracks with the old sudo vi / !bash and similar tricks, but the goal isn't to protect against hostile privileges users, its to know what happened so that when John is on holiday you can see what he did to fix the problem you had last week.
sudoedit(8) has been around for a long time and it solves this problem.
The idea for sudoedit is that it allows you to allow non-root users to safely edit files, and if they shell out of their editor then they've not gained root rights - they edit a temporary file as a regular user and then sudo moves the file into place after it is edited.
Unless you have an system with its own auth and audit capability connecting as root, shared accountability is bad. People do dumb shit, including illegal shit.
So, account with sudo capabilities is better than then one which is sudo by default.
However, it's somewhat less secure than sudo-enabled account with password requirement. If your SSH key is somehow compromised (unpassworded keyfile or attacker had gained access to ssh-agent's socket, or you've ran a network-listening daemon from your account that had an exploitable RCE) you're a little bit more safe if attackers won't get root access. This only works well for noexec $HOME, of course, as attacker can't mess with your .*shrc and trick you into entering the password.