On-chain Authenticity and reputation. Though there are some projects trying to develop NFT based certificates and stuff, there's always a question of authenticity since they can be transferred and traded in a secondary market. And also many of them are centralized. As Vitalik said, "If someone is looking at your POAP, they are not interested in whether or not you paid someone who attended some event. They are interested in whether or not you personally attended that event. Proposals to put certificates (eg. driver's licenses, university degrees, proof of age) on-chain face a similar problem: they would be much less valuable if someone who doesn't meet the condition themselves could just go buy one from someone who does."

If you could simply trade such certificates, it doesn’t have any value at all. So it should be bound and non-transferrable to build authenticity around the token. The more authentic you are, the more reputation you acquire. Given the pace of development of metaverse, there needs to be somesort of on-chain reputation system that should be able to find how genuine/authentic a person is without revealing personal info. I think that ENS is growing rapidly at the same time, so literally everyone’s on-chain identity will be owning an ENS domain. So what I’m trying to build is a trustless, open and decentralized system that helps everyone to issue on-chain, non-transferrable, ERC721 compatible badges tied to the ENS domain.
It has infinite amount of usecases, For example, Devfolio could use ENSBound Badges to issue their privileged limited edition badge for best performers in the hackathon. So the user's with the badge issued by Devfolio on thier ENS domain will provide increased reputation and trust without the need for sharing their personal info. Hence ideas like ENSBound badges can be used to prevent fraud or unauthorized use of digital assets, by ensuring that the badge is only valid for the user to whom it was issued to.