It's being used very differently, though, as the domain-as-username is far more prominent in the ui. People aren't really using subdomains, except for the .bsky.social default, and in most cases someone's username will lead you to a website with more information about them, or a direct affiliation with them. It's functionally similar, but the UI/UX makes it feel like far more of a "verification" than nip-05 does.