"An important property of a blockchain that users really value is permanence. A digital asset stored on a server will stop existing in 10 years when the company goes bankrupt or loses interest in maintaining that ecosystem. An NFT on Ethereum, on the other hand, is forever."
This is wrong 2 times.
First, there is no general requirement of permanent storage. Its not important at all. It solely depend on the use case. Thats why it is very much inefficient to use a DLT with that property to move value (btc/eth etc.). I dont care how my coins was moved 10 years ago. The only storage that is relevant for me, now, for value transfer is the current undisputed state (aka the balances). Sure the Tx history has use cases and people who need them should store them but making that a technical requirement is only going to degrade performance and drive up Tx cost.
BTW cash does not have a recorded Tx history who thought "p2p cash" should? Its only because of the way BTC works (chain of all Tx) that this "believe" became common. Its technically not needed at all. There is absolutely no reason to recreate the whole chain to come to the current state. You either use the current state or you cant participate. If you would find an error in the chain whatcha gonna do about? Nothing. The current majority accepted state is all that matters. The "validation" is placebo it does nothing. And by running the exact same software as anyone else your validation would simply do the same error if there would be one.
Second, the "forever" is a blatant lie. There is no way to know. Its will exist for however long at least someone is willing to store it. Exactly the same is true if storing is optional. But without the downside of crippling the performance and impose cost on the people running the DLT. The cost for storage should be paid by the user of the storage. If I can impose cost on all participants of a decentral system for all eternity with a one time payment then the system is deeply flawed. The possibility for abuse can be limited by simply making it expensive at any given time. But this obviously reduces the usefulness of the whole system especially for value transfer. The idea of an internet of value is to make value move like data, dirt cheap and decentral so no one takes a cut.