Universal basic income is a form of taxation system last time I read it being discussed, government costs money its not the pay but tax alteration that matters most to this idea.   Increasing efficiency across a population could be a massive positive.   The reason its relevant between tax and welfare and the benefit it brings is to remove the division or any discouragement to produce from those on low or no work.   People on any welfare system do continue to pay taxes like many in society, the highest % of taxes can be levied on those with the least income and its quite ironic that the lowest burden is on the richest.
   I dont have any problem with very prosperous people, every country requires success but the benefit this system might provide is to flatten the apparent tax gap so that all have a basic livable situation and will pay taxes on any extra income.    Welfare is a bit of a swearword because of how it can create an under class who are worse off if they attempt any change in circumstances, theres surely better explanations but I just wanted to mention there is certainly a possibility of some merit to the system and like you say its not a new idea.