Regarding "sickness", the severity is important to know. If UBI enables people with slight depression issues to just give up working entirely, UBI could be entirely counterproductive by accelerating depression's spirals of inactivity.
And this completely ignored the issue of inflation that comes with society wide UBI.
The whole notion of UBI is nonsense. Rather than throwing money at people to spend on broken institutions like Education and Healthcare, let's reform these institutions in the first place to make them more affordable and effective.