Assuming everything else stays the same, if a swarm of robots enters the economy and starts doing a shit-ton of everyone's work at a tiny cost, then productivit

Assuming everything else stays the same, if a swarm of robots enters the economy and starts doing a shit-ton of everyone's work at a tiny cost, then productivity skyrockets and we all start collecting unlimited social security checks starting at age 62. But everything else won't stay the same. Consumers will start to demand more from the businesses and governments that use these robots. Businesses that don't get more robots -- or more expensive robots -- will be left behind. Pretty soon the productivity miracle disappears and we all have to work until we're 70, just like before.