Let's discuss about new use case that's still not on the blockchain/crypto yet,
It's quite difficult to discuss this. Almost all of the ideas related to blockchain development have already been taken by so many developers. Even some developers were also creating a nonsense idea that can't be real. I think that the room to explore the idea to be connected with the blockchain became even smaller and this time the replication of the same idea is very popular among cryptocurrency developers.
It is not about the idea, it is about taking the blockchain further into something new. Just imagine how we moved to decentralized finance (defi) last year, not that it was teh first time it was ever created, but it was certainly the first time it got super hyped, or look at how NFT is popular, or look at metaverse. These did not existed just 3-5 years ago, but blockchain existed for 10+ years now.
This is a proof that blockchain could be used for many different things. Do not just imagine the current blockchain we have and how it could be used, think of the blockchain idea itself, and how it could be improved. If the original bitcoin blockchain was the only blockchan there ever was, then we would have been in a much worse market. What happened was the fact that people took what satoshi did, and improved on that and then used it on their ideas.