Furthermore, what if the exact same nft is minted on another blockchain? Now two people can "own" it!

It's all meaningless hype.

But the tech is good and it does have actual use cases (i.e. concert tickets).

 

This is going to supercharge the NFT access to so many more users. Brilliant move Coinbase.

i was with opensea but now with binance they have very easy website with big crowd ! 

The NFT project Communiity on opensea is the future