Todd is a saint for the work that he does here. Ultimately, like many other OpenBSD-related decisions, sudo was replaced by doas because of all the security-related issues with the code. Oftentimes, OpenBSD will replace a very functional solution, that has too many security issues, with one that has far less security issues and is, simply, good enough.
It doesn’t remove a bit of how impressive the dedication of Todd C. Miller is of course.
These are two solutions with a common core goal but greatly different concerns.