So, you think sickness benefits, unemployment benefits, state pensions, etc are somehow not 'giving money out'? They are somehow 'measured'?
The whole point of a (properly designed) UBI is to replace ALL of that, with a single right of income.
The advantages include removal of the huge amount of bureaucracy, management costs, corruption, and fraud.
Basically it means everyone gets treated EQUALLY, and you would be amazed how many people hate that idea.
Usually because THEY want to be the ones deciding who is 'worthy' of support.
The cost is self-adjusting, because basically all countries have graduated income taxes, and UBI is also taxed, so people with large incomes
just end up repaying most of it in tax anyway. A country should use a combination of personal tax, and savings from the scrapping of all the broken
other forms of social benefits to fund it.
Of course that is putting it simplistically, however that is the formula of a true UBI, which many haters (usually those who currently profit from control
of existing welfare schemes) work very hard to ignore.
UBI is not 'free money for all', it is an acceptance that welfare is a sensible right in society, so we should remove the broken and inequitable systems
that current exist, covered in bandaids, and replace them with a simple single system that treats everyone equally, is low cost to manage, and almost
by definition free of corruption and fraud, because it is so simple..