Really? Today's computers are cheaper and better than computers were in the eighties.

You are missing the context. Advancements in computer technology were a result of research and development, not someone ruthlessly cutting costs.

These are symbiotic. The research and development pays off because somebody else is willing to ruthlessly buy the new, cheaper/better option instead of the safe traditional choice. Mainframes gave way to minicomputers which gave way to microcomputers which gave way to laptops and now to mobiles.

There are many tasks that machines do today that humans will never outcompete again, and they do it at a superior intersection of benefits and costs. Using a heuristic like that is too lazy and brittle here.