> I'm not convinced that the sum total of all these benefits plus the current infrastructure that is needed to maintain, dispense and detect/punish abuse on them is significantly larger than the total expenditure on UBI.
Most western social democracies publish the data on costs of running departments and numbers of working age people in employment or receiving each type of subsidy, so we know that the admin costs are negligible compared with the cost of paying a living subsidy to an enormous number of working age people who aren't claiming disability or unemployment benefits, generally because they don't need the money enough to take the steps necessary to claim it.
Most western social democracies publish the data on costs of running departments and numbers of working age people in employment or receiving each type of subsidy, so we know that the admin costs are negligible compared with the cost of paying a living subsidy to an enormous number of working age people who aren't claiming disability or unemployment benefits, generally because they don't need the money enough to take the steps necessary to claim it.