The example of sudo is not a good one. Sudo actually has an incredibly large feature set, most of which is related to it having fine-grained access control. Things like "sudo -e" allow a sysadmin to allow a user to only modify certain files using their editor (while the editor itself doesn't run as root so it can execute malicious code as root). Sudo is a very cool program (there's even a book on it buy the OpenBSD guy who maintains it IIRC). The point being there's a reason for the complexity, and pretending that the solution to making secure programs is to make them simple is ignoring the constraints of the real world. We need complex programs that are also secure. Yes security is hard, if it wasn't lots of people I know would be out of a job.
Well, OpenBSD deprecated sudo(1) in the base install in favor of the vastly simpler doas(1), because of complexity concerns.