Like Blockchains, the value of the US Dollar is a shared version of reality as well. How likely is it that anybody will work for paper onto which somebody printed the pictures of dead men? But they will work for US Dollars and get sold iPhones for them.
The ledger here is culture, in case of the US Dollar even cross-cultural agreement, that the US Dollar does serve as storage of value, the value of work or the value of an iPhone and that it does so over time.
In this, philosophically spoken, Blockchains are more real than the virtual value of the US Dollar, for which there is no ledger you can access to operate digital processes.
And while there are tons of shady reasons to keep cash money circling, one good reason to keep it is that it represents a cultural agreement which binds people together, something all people share physically in their brains. Doing away with it would eliminate a band that bonds us all for something machines can handle better than we can.
P.S.: IMO Engineering will be a much bigger user of Blockchains in terms of turnover than VR. Especially coupled with 3D-Printing, Blockchains will lead to a massive explosion in productivity and innovation in engineering.