How do you determine that a "lot" of people will prefer not to work? That assumes that they take no joy in labor, have no desire for the luxury and enjoyment that an increased income would bring, and are uninterested in the social advantages of being employed and financially comfortable.
The small set of people who are only motivated to work by the threat of destitution, and who would be satisfied by a pittance and choose not to pursue further labor, are people whose labor was likely never worth much in the first place.
How much is having your office trash can emptied worth to you? floors swept? toilets cleaned? ...and other labors which aren't worth much, labors which have little joy therein, yet cannot be abandoned completely? Offer those current workers (of whom there are a lot) the option of doing nothing yet getting paid the same pittance they are satisfied with (and many are), heck yeah they're gonna quit and you're gonna start wondering who's gonna empty the trash and clean the toilets while you're enjoying your labor.
Their labor may not be worth much. It still needs doing, and you're compelling others to take away any incentive to do it.
It isn't worth so much to me that I would prefer people be compelled to clean up after me under threat of destitution, no. I want them to be paid what their work is worth, which is the amount a person free of the threat of poverty is willing to accept to do the work. That might be a lot more than it is now. It might not be much more at all.
If it's uneconomical to employ people solely to do those jobs, then the jobs can be automated, or fixtures and processes can be changed to reduce the need for that labor.
This will open up the jobs to teenagers- those not eligible by age to receive the basic income. They learn value of work, value of money and will be better off then many teenagers that can't get gas money/college savings since those jobs are taken by those that can't find any other work or have no more ambition to live more than to survive.
Well, maybe people will clean their own toilets and empty their own trash then. I do those at home (as do my housemates) because I like having a moderately clean home. If nobody else was cleaning the office I worked in, I'd clean it too, because it's basically a home.
So go calculate your "fair share" of office trash cans, toilets, and etc., work out how much laborers are being paid to do your "fair share", give them their cut out of your wallet, tell them to enjoy the money while you do the work, and proceed to clean those things yourself unpaid. If you're not actually going to do those things (but they still need doing), then re-hire & pay those laborers to do the work after all on top of the amount you're paying them to not do it.
Remember: they're hired to do that work because your time as a professional thinker is much more valuable than you spending hours doing mundane tasks. Better you spend an hour writing software for $X and paying someone else to empty the trash & clean toilets & etc. for 0.1x$X, than for you to spend that hour doing those mundane tasks for $0 while being compelled to still pay that someone 0.1x$X.
So yeah, because you're not really going to do all those little things you rely on low-wage laborers to do, you're going to DOUBLE their pay (giving them that "minimum" amount for not doing anything, plus giving them that amount to do that work after all) with no increase in output, and a likely decrease in work done because by definition that minimum guaranteed income is enough to live on.
The small set of people who are only motivated to work by the threat of destitution, and who would be satisfied by a pittance and choose not to pursue further labor, are people whose labor was likely never worth much in the first place.