The thing is, if everyone’s retired and nobody’s working,

Where do you get the idea that nobody is working with UBI?

UBI isn't supposed to be your entire, or even your primary source of income. The most basic concept of UBI is supposed to be enough for a roof over your head, rice and beans in your belly, and that's about it. It's supposed to cover the absolute essentials, not your entire lifestyle. It is supposed to remove the desperation of subsistence.

When a man is drowning, he'll do anything to survive. When his lungs start filling with water, he'll drown his wife and kids just for one more breath of air. When a worker is desperate, they will take any work on any exploitative terms that are offered, just to put a meal in their belly. That desperation drags down wages and conditions for everyone. The fundamental purpose of UBI is to ensure that even the most desperate among us aren't forced into exploitation, and in doing so, drag everyone down with them.

There is no shortage of labor. We have a massive excess of labor. We have so much labor available that even though everybody currently needs to work, wages are so low that nobody has any money to spend on anything but essentials. The economy is stagnating because everybody is working, but nobody is buying anything.

UBI is a long-term solution to this untenable situation.

Millions of people work for free every day, we call them volunteers. Many of our institutions including hospitals, parks, schools, sports leagues, museums, food banks, community theaters and zoos depend on volunteer staffing to run their programs.

When I hear someone say no one will work if they aren't paid, I hear projection.