The premise of it being universal is that it doesn't have an explicit phase out and instead it's implicit in the tax system. Obviously someone making six figures is not going to be a net recipient, but they would still have the money deposited into their account. The amount would just be smaller than the amount they're paying in taxes.
The advantage of doing it this way is that it makes it clear what's going on. Right now we nominally impose low marginal tax rates on the poor but their effective marginal tax rates are high because of benefits phase outs, so their effective marginal tax rates are higher than the wealthy. With a UBI you replace the benefits with cash payments and eliminate the phase outs, but also flatten the tax rates so the poor are paying the same effective marginal rates as the rich, instead of higher ones.
The result would be that the poor pay slightly lower effective marginal rates and the rich pay slightly higher ones (although you don't even inherently have to do that; it depends entirely on the tax rate and the amount of the UBI), but the overall system is much simpler. And the consequence that the poor are paying higher effective marginal rates than the rich, which was presumably never intended, goes away.
Right! It also lets you eliminate the means testing part of the system that makes people jump through humiliating hoops to show that they’re poor enough to need a handout, punishes people who are working too much by taking away their benefits, etc.
The advantage of doing it this way is that it makes it clear what's going on. Right now we nominally impose low marginal tax rates on the poor but their effective marginal tax rates are high because of benefits phase outs, so their effective marginal tax rates are higher than the wealthy. With a UBI you replace the benefits with cash payments and eliminate the phase outs, but also flatten the tax rates so the poor are paying the same effective marginal rates as the rich, instead of higher ones.
The result would be that the poor pay slightly lower effective marginal rates and the rich pay slightly higher ones (although you don't even inherently have to do that; it depends entirely on the tax rate and the amount of the UBI), but the overall system is much simpler. And the consequence that the poor are paying higher effective marginal rates than the rich, which was presumably never intended, goes away.