As technology advances, some jobs are going to disappear, but hopefully, those new technologies also add new jobs that didn't exist before. Back in the day, it used to take a whole lot of people to harvest a field. Now it's all done by one guy and a big tractor or two. But people need to build those tractors, program the controller, repair them as they break, etc. More kiosk and self checkouts are going to need techs and repairs. It's just how things work. It probably won't be long when some store switches back to using actually staff because it's a unique feature when no one else has human staff anymore. Like how people buy Amish furniture now because it's like the only way to get handmade furniture today.

Saying to leave a mess so a company "has" to hire a janitor is just a dumb way to express the idea that there needs to be more jobs.

I get the fear that if automation keeps picking up, there may be a time where there truly aren't enough jobs to go around, (A.I. is really fucking scary at how fast it is improving) but hopefully if technology advances that far we'll also see improvements in agriculture, housing, and power generation to the point that people don't need a shitty $15 an hour job or a "free" paycheck just to not starve to death in the street because hopefully providing clean water and food won't be as hard as it is now.

Universal basic income is just a dumb idea. You are taking money from someone who works hard for a living, making life harder for them, just so someone else doesn't have to work for a living. It is the core concept of communism. What happens when no one wants to work because they can just get the free income? Did your teachers really never do the average grading experiment with you? Instead of getting the grade you actually got on an assignment, everyone just gets the classes' average grade. No one should fail, but at the cost of a few good students getting worse letter grades. It lasts for one or two assignments before most people just stop doing the work and now everyone is failing because the few people that are still doing the work can't get high enough grades to average a whole class of zeros out to more than Fs.

If it's something you are really concerned about, then really try to find a solution that doesn't involve forced labor on one group of people, so another group can benefit. Our ancestors did that shit for years back when it still took people to harvest a farm, and most people are still pretty upset about it to this very day.