UBI doesn’t give any power to those who own the means of automation, nor does it take power away from laborers. Automation does that. Automation reduces the leverage of the laborer by reducing the capitalist’s reliance on labor.

We have the same leverage regardless of whether we have UBI or not, but the leverage of employers is reduced with UBI. That said, if more people opt not to work thanks to UBI, then the people who choose to work will see their leverage increased.

Not sure why you think there wouldn't be any more need for labor, unless you're thinking of some far future post-scarcity society where literally everything is automated. A UBI implemented now would give the working class even more power because they'd be able to actually use their labor as leverage instead of being forced to choose between working for shit pay or starvation.

No, the automation technology gives them that power, ubi is a consequence of it. The more productivity per worker a company can achieve, the fewer employees they need.

You really think as technology advances and companies implement more and more of it, that companies only end up with more leverage if the local government is doing UBI?

UBI is welfare product that helps low bracket earners. If the tax code was functional it would be paid for by the corporations and 1% themselves and even so it's still extremely helpful where it's implemented.