A lot of people do want to do more, especially in some corporate contexts people run very complex sudo setups.
Consider something like Linode; maybe you want some of the more experienced support people to issue some commands on some machines, without having full control. And you've got a gazillion machines so you don't want to setup each one individually (as well as revoke access once they leave). Things can get fairly complex pretty quickly once you move out of simple settings.
For my desktop machine, doas is perfect. For our servers it's fine too because we have just a few people with access. But I'm not everyone of course.
doas was explicitly written to NOT cover all use cases, and that makes it better for the (simpler) use cases it was intended to solve, at the price of not covering other use cases of course.