Another benefit that needs to be mentioned is it provides an unconditional safety blanket for anyone who has a job. People who now feel they are stuck in a job for fear of being broke wouldn't feel as stuck under a UBI. This is a huge benefit for the majority of people. Many workplaces would improve, especially the worst ones, as people wouldn't feel as stuck in them, this severely limits the degree that employers can treat their employees badly. For the self employed it gives them freedom to leave their occupation and do something else when things get bad for whatever reason. Even people who are financially secure and have their own wealth as a safety net are likely to benefit from workplace improvements, even if the money from a UBI itself is a lot less important to them.

In short, the benefits to the already employed should not be left out.