sudo.rs is a really weird direction for an evolution — it re-implements a complex piece of security dropping some arbitrary choices but keeping it pretty complex. It has the exact same security model. I honestly can't understand the appeal.

If you want something similar but simpler, go for doas.

If you need all the features in sudo, keep using sudo.

If you want to try new security models, try s6-sudo, or any other of various tools out there.

sudo-rs keeping the same name is actually a worse breakage — because it doesn't have the same API as sudo (as described by op), but has the same name and pretends to be a drop-in replacement while also not being a drop-in.