Yeah, Sudo has been around for ages and is in pretty much every distro. So Doas just hasn’t really taken off due to inertia. You can install it yourself in many distros, but people tend to default to what they know. I’m not sure if any distros default to it. Also tutorials all over the internet use “sudo” so it kinda embeds it more as THE tool.

It’s similar with a lot of the core GNU utilities. For example “ls” lists directories and it’s everywhere, but there are actually better written newer alternatives. They just aren’t as widespread because people tend to use the GNU utilities together. I personally like eza for example.