Should we give everyone hip replacements rather than bothering with appointments and need? Think of all the administration saved! Just book everyone in!
Except now you’ve spent a trillion on hip replacements, the people who actually needed them are getting less support and on a huge list, and you’re just pointlessly operating on random people.
Hip operations are a weird counter example to refute UBI. They're obviously not universally applicable and are more expensive in cost and resources than the administration overhead. That's leaving aside the ethical issues of giving people unnecessary surgery.
Let's say there's three people, making $0, $10K, and $100K annually in pre-tax income.
The first person has to stand in line to get welfare. The second person has to prove that they deserve the tiny amount of of welfare they may be entitled to, chewing up the time of government bureaucrats in the process. The third person has to pay income taxes, deal with refunds, tax write-offs, etc...
All three people already involve the government, have to deal with paperwork, and this overall process generally costs non-zero money to implement.
Let's say these people pay $0, $0, and $30K in taxes, for $0, $10K, and $70K net income.
With UBI, the tax brackets are adjusted such that the person making $10K pays $5K in taxes, and the person making $100K pays $40K in taxes. These are just parameters (numbers) plugged into an existing mainframe.
The government now has an additional $15K of tax revenue.
Then everyone gets a "tax refund" of $5K, as-if they had a bunch of business expenses or whatever. Again, just a parameter in the tax dept mainframe!
Now the net incomes are: $5K, $10K, and $65K.
The beauty of this system is that no humans are involved. Nobody has to evaluate your assets, income, side-gigs, or whatever. Nobody has to care if you're "too rich" to get government assistance because everyone gets government assistance.
It's cheaper because it's just numbers plugged into a mainframe that already processes everyone's tax every year! No additional expense is required: no new department, no new staff, no new offices.
In fact, vast numbers of government drones can be made redundant, because... they're redundant now. Whatever they were getting paid before (a lot) can be added on top of the additional tax income. Billions, certainly, in most countries.
Instead of pushing paper around, they can now join the commercial workforce and hopefully be productive members of society instead of telling disabled people that they don't deserve help because they have a valuable painting on their wall they inherited from their grandmother.
It seems challenging to get everyone to agree on a fair number.