If more people were employed during less time, we would also need more administration.
Not to mention that there are at least two sectors where there can never be enough employees: medicine and education.
So I can see how naturally the system has prioritised this way of working, but despite the efficiency I think we need to do something to normalise 20-30 hours as full time. Give people less iphones and more hours in their life.
This combined with doing something about housing prices seems like it could work.
That's also why building homes is so costly. Transporting non-local materials costs more than making them near. Then you need to support builders, plumbers, electricians...
That's not the world our Overlords want for us. They want us to literally work ourselves to death making them richer than Gods as cheaply as possible, and then fall over into a convenient nearby pit and bury ourselves for their convenience.