The difference is that bitcoin is of dubious value in terms of productivity gains.
That's just completely incorrect and demonstrates an ignorance of the history of computers.
>And the internet.
Once again, this statement demonstrates an ignorance of history. The early internet was a monumental research and engineering effort funded by the U.S. military because its utility was completely apparent before it was even built.
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For those reading this who are perhaps a bit more open minded, it is not clear what the future productivity gains will be from moving capital allocation out of the hands of central banks into the hands of Bitcoin hodlers. To beat a dead horse, If 51% of energy is devoted to securing btc, but capital is allocated in a way such that productivity increases x%, where x offsets mining/transaction costs, what's the problem?
Of course not, why would you even think that? What about a technology being obviously useful implies the need to make arbitrary predictions multiple decades into the future?