With such absolutes we're entering wild hypothetical territories.
An alternative viewpoint would be that no bullshit job => everyone does a humane job with a purpose. Wouldn't that be nicer than breaking one's body or mind for a soulless job, artificially so just to get money to put food on the table? I think we're fairly happy to not have to hunt for food and plant crops.
A second alternative would be that millions (90% so... billions? all?) being "unemployed" would mean (as you seem to imply) they wouldn't get paid (or they would through some flat social revenue) and money would rapidly cease to have any meaning as we understand it.
Both cases converge to a post-scarcity economy[0], one popular example of which is the Star Trek economy[1].