Not really, because you’re now going to make it do more, i.e. incorporate the functionality of sudo and expose it to user input. So unless you can prove that the newly written code is somehow inherently more secure than sudo’s existing code, the attack surface is exactly the same.
The attack surface will be a systemd daemon running with UID=0 instead, because how else are you going to hand out root privileges?
So it doesn’t really change anything to the attack surface, it just moves it to a different location.
That already exists.
systemd-runis already available today. So the attack surface would be smallerNot really, because you’re now going to make it do more, i.e. incorporate the functionality of sudo and expose it to user input. So unless you can prove that the newly written code is somehow inherently more secure than sudo’s existing code, the attack surface is exactly the same.