Your argument pays no attention to how economic behavior changes due to existence of UBI, ie, how many people choose to work less and thus drop out of the pool of people paying in.

It doesn’t really make sense to me to live in a world where people are given money by the government while simultaneously expected to pay taxes. Its a high overhead when the same could be achieved by printing money and handing it out to everyone equally (which acts as a redistribution of wealth same as taxing the rich and paying credits to the poor, since it devalues the dollar as more supply is added)