UBI in theory means that everyone in the world should receive a modest income (in the order of $2/day). This is something that I would support.

UBI proposals in practice means that an exclusive in-group gets gets the wages the comfortable middle class wages for free and outsource all their work to an out-group that doesn't qualify for UBI. Working conditions for the out-group are slow to improve because they have very little political power. Meanwhile, the in-group stagnates and becomes completely dependent foreign work paid for by free money. This is exactly is what happens in the Gulf oil nations.