>The government receives less tax revenues because 20% of the population is no longer working (and paying taxes).
The assumption is that machines exist that are more productive than all these people no longer working. If these machines didn't exist, then these people would still be productively employed.
Except if consumers don't have jobs they won't be able to purchase the products made by machines, therefore the owners will NOT make the money, and the economy will enter into a "death spiral".
The assumption is that machines exist that are more productive than all these people no longer working. If these machines didn't exist, then these people would still be productively employed.