Some users want a different id for social, gaming, Pinterest and other utilities because they desire different personal brands, but also users may want nip-05 providers with the same name due to add on features of the registrars that extend their use cases across their interactions on nostr.

Another use case is that if you own or run Multiple Companies, you may want to have a nip identifier for each of the domains related to those companies. Let’s say for your registrar and five other projects that you run, you may want to have the same short name at multiple domains to identify that you’re a good actor for each of those services

Collecting identities is odd . . . to you. To me, this gives people or groups more options with a simple, ignorable if you don't want to support it, array.