I disagree - a UBI means that anyone who's able to live frugally may, at any time, retire. This gives enormous bargaining power to workers, as if the pay is too low then they can say "fuck it, I'm moving to <insert rural ghost town>, buying an abandoned house for $1, and living off my UBI".
Not only does this put downward pressure on rent, it also encourages jobs to be more available in rural areas, as people will move to there for lower costs of living instead of moving away because it's unaffordable due to lack of jobs/UBI.
Your wage is not determined by your productivity, it's determined by your bargaining power (your Best Alternative To Negotiated Agreement (BATNA) being the main one, but how unique your skills are determines your employer's BATNA).
In other words, employers will employ you for any amount that still lets them make a profit off of your labour, but they will pay you the least they can get away with paying without you walking away. Some people literally can't afford to walk away, and they're the people who are paid dogshit wages. A UBI would let them walk away until their job calls them with a good offer.