[mitthrowaway2]

For a reductio ad absurdum that might illustrate where your analysis falls down, consider how someone with net worth of $0 and someone with net worth of $100k would each be differently affected by getting a $5k handout, accompanied by a 10% decrease in the purchasing power of a dollar. The end result is not the same as the status quo.

The intent is not to make everyone richer, but to redistribute wealth in an equalizing direction. (In fact this might also make everyone slightly richer on average in real terms, because of second-order effects related to economies of scale that make it slightly easier to meet the growth in demand when wealth is distributed more evenly).

Of course, the decreasing value of the dollar is an undesired side-effect of any government spending; this is why you counterbalance it with taxes to pull money back out of the system and control price growth. These taxes don't exactly cancel the UBI if they disproportionately fall on the wealthy; this is why I like consumption taxes, which fall more heavily on people who have more money to spend.