I do agree with you on the instant payments can be done in fiat already in almost all the cases.
But why it can't work is because fiat will not pay the workers every day. But the bigger problem is that they are not paid for the work but for the time.
That combined with the ability to do split payments is why I think this vision could be possible. It is a holistic vision with all the components working together.
If we talk about just one aspect of it is becomes the conversations like which blockchain is the best.