What exactly should people do if they're not employed?
Note: I don't think this will happen. I think rich people now would rather let people starve so they could save the price of the 15-Second Ad Burger.
We have incentivized sociopaths to run things in the name of efficiency. We will either realize this is a false goal, remove all those people from power and influence, and live in a post scarcity society... Or we will all suffer the consequences.
If the food has a meaningful cost, or the adverts has meaningful revenue, then there is meaningful labour to earn money to pay — directly or indirectly — for the food and/or advertising.