I suppose it depends on what you're talking about specifically. If you are talking about a specific NFT collection, it's a lot like the Second Life example, actually. You don't have any guarantee that value will be maintained post-hype, so you need to be careful with your investments and find teams/projects that you believe have staying power. If you're talking about PFP NFTs in general, the argument is that your digital self will need to express itself in the metaverse - I'm working on a big post about Loot which goes into this more, but they are actually creating characters based on your Loot metadata. If you're talking about NFTs in general, the Ethereum ecosystem and object permanence will create long term historical value for many of these pieces, e.g. Curio Cards, MoonCats, and Etheria were all dormant with unfinished mints from 2017 through March of 2021 just about, but now are exploding in value.