I think using your own domain name does give it more credibility but a lot of users dont control their own domain name so then its value is questionable
Discussion
That's the thing, my understanding of what NIP-05 is supposed to do has been rendered mostly useless because there are so many services, and some clients, that offer a free NIP-05 address and pass it off as being a simple Human-Readable Identifier. If I'm understanding NIP-01 correctly, a kind 0 note already provides an HRI that clients can use for search queries. So it seems to me that people are completely misunderstanding what NIP-05 is meant to accomplish. Then again I could be 100% wrong here.