As the cost of labor drops the costs of providing free services will also drop. I can see the world of 2100 having a 95% unemployment rate and zero social unrest. A 10% flat tax could easily support a standard of living well in excess of what we are used to today and the few people that are employed could have access to the new inventions well before the rest of the population.

Put another way, I would rather do most things with 10 million today than 50 million (inflation adjusted) in 1900. You could get more manpower back in 1900, but I would rather have 1 guy using a backed loader than 10 people using shovels.