If someone is currently on $25k and gets a $10k basic income, their employer can lower their salary to $20k and they'll still be getting $5k more than they were before. (This won't happen immediately because people will be reluctant to take pay cuts, but I think it will in the longer term.)
Exactly how much of this difference the employee and employer capture in the longer term is a concern, but I think giving people the option to quit without starving will go a long way towards empowering them to insist on fair pay. I also think a result would be an increase job quality, because I think a lot of people would take a pay cut to work somewhere less awful if they could afford it.
Of course that money comes from taxes, so there's still a cost somewhere, but I'm not as convinced progressive taxes on the wealthy will have quite as big an impact on the costs to produce basic goods.