There must still be a need for the 40 hour worker. No company in its right mind is going to pay someone for 40 hours if they can get the same amount of productivity from someone who can accomplish it in 20 hours.

Companies would rather increase productivity with the same amount of workers/hours than keep productivity the same and scale back a worker's hours. They would rather grow the company and pull in more profits than remain stagnant. Thus keeping the same amount of workers working for the same amount of hours plus using automation/technology could equate to a greater output. It all comes down to dollars and cents - and what the company is trying to achieve.

Technology and automation has its advantages but quite often a human has to oversee the machines and maintain them. Think of your car - it is equipped with technology that cars years ago did not have, yet your Tesla still needs to be supervised by you. Medicine is ripe with technological advances but scans must still be set up interpreted by humans, human surgeons must still direct the Da Vinci Surgical System. . .

Technology and automation can sometimes increase problems due to their complexity and venerability to system glitches, software problems, hardware breakdowns. . .

Machines do not always make things easier and faster. Sometimes they screw up big time - and those screw ups need humans to fix the mess.

And humans are for the most part notoriously slow to change - even when that change is beneficial, most humans seem to prefer the familiarity of the same ole same ole.