How much money have people spent on Bitcoin because of PoW? All those billions were spent because as a speculative vehicle they thought they’d see even greater returns but that doesn’t mean that any other service will see a correspondingly high willingness to spend large amounts of real money.

This is especially challenging in the social space where people are accustomed to not paying and you have significant network effects from anyone being able to sign up for free. Bitcoin’s transaction fees are one of the major reasons why it failed as a currency and that has orders of magnitude fewer messages.