Unconditional Basic Income (UBI) is based on the assumption there will be no jobs for most humans in the future.
What we have today is CBI or Conditional Basic Income which is conditional based on the assumption that you can motivate people to find jobs and that jobs will be available for most. If there are always going to be plenty of jobs then UBI makes no sense.
But if you believe that there be fewer and fewer jobs for humans, then UBI make a ton of sense.
I am of the latter belief.