For collections, nft will never be destroyed even if the project founder or artist leave it, your token will always be stored on the blockchain. For example, as for me, I will never sell my Pixelglyphs which a very attractive project I discovered recently which uses algorithms to generate pixel avatars on the blockchain, which is similar to the default avatar on github. Each avatar is different, and there is no so-called rarity and attribute. Even it's price go to zero, I will buy as much as I can, because I just like them and they will always belong to me.
For identity authentication, the popularity of cryptopunks not only because of its special meaning (almost the earlist NFT program) and collection value, but also because of the representation of a group of top players in the crypto currency area. For example,famous people from Twitter and company spent tens or even hundreds of eth to buy cryptopunks to show their vision, ability, and have chance to make friends.
What do you think of the prospect of NFT, and why do you buy NFTs?
I am afraid you are mistaken that you can’t lose your NFTs. The thing is that it is one of the issues that demand to be solved in terms of NFT. Storage of them is not very safe now. It means that one day you can enter your storage and see Error404 instead of your picture. It can happen, because pictures, videos or music attached to NFTs are stored on centralised server that can also break down.