>Perhaps in 20 or 30 years we will have something akin to plan9 or inferno composed from nodes on these networks?

Seems highly likely to occur within less than a decade. Tops. Just not on the blockchain. Likely something not-blockchain, e.g. https://ecsa.io/ (which /interacts/ with the blockchain, but isn't blockchain based.)

People massively underestimate just how fast technology progresses at the moment.