> the work put into the network is exactly the scarce digital asset
Not even a little. The scarce digital asset is the slot on the distributed ledger. That you currently need a load of energy to reassign digital ledger slots is an accident of history - because it was the first way that anyone worked out how to run a secure distributed database across mutually distrusting nodes where you don't need to know the participants in advance.
The work is not the scarce asset. If you doubt this, consider: the 'work' required to mine a block (and so 'create' the block reward) changes based on how much hash power the network has, and varies quite substantially between the early blocks and now, yet the bitcoins mined then are worth the same as bitcoins mined now. If lots of miners stop mining BTC, then the amount of work required to mine the next blocks will reduce, yet the bitcoins created with the lower work requirement will be worth exactly the same as bitcoins created with higher work requirements.
Obviously, in a PoW blockchain, the work is extremely important, since a PoW blockchain can't remain secure without significantly more work being done by the network than an adversary can marshal to attack the network, but that's an entirely separate thing.
You can take a valuable painting, burn it down to ash and use the ash to make ink to do a stick figure drawing. The stick figure drawing doesn't magically become 'a store of value' because you destroyed a valuable painting to make it.