Social Security and Medicare are both very popular with those receiving them and both very efficient with very little overhead. Soc Sec has an admin overhead of less than 1%. Medicare's overhead is 2%. The overhead of private healthcare is on average 12%.
As for what Medicare covers, again those who have it love it, and it can be compared to Silver and even Gold plans as rated by the ACA market exchanges.
Meanwhile, UBI is meant to replace over 100 government programs (but not Medicaid/Medicare), and over 100 tax credits to simplify the tax code. Why give someone $3000 off their taxes for owning a house if they are getting $12000 cash from UBI?
The net increase in taxes required for UBI is not as large as you seem to think it is. In fact, it would be a reduction in tax burdens for 8 out of 10 households, which likely includes you. If your taxes go up $7000 to pay for $12000 in UBI, that's a net gain of $5000 and thus a net tax reduction equivalent to a $5000 tax credit.
The fact that those people enjoy receiving free money, proves nothing, except their bias.
Social Security is insolvent: it brings in less money than it pays out.
I have been looking for costs on your articles, i'm glad you mentioned it. So if everyone in the US, 320 million people, receive $12,000 a year, that's a total bill of $3.8 Trillion, that is more than the entire current federal budget. And you want to keep Medicare, so add another Trillion to that. Those two programs alone would be about double the current entire federal tax revenue, and that sounds cheap to you?
What about those other 2 out of 10 households, do you plan on robbing them at gunpoint yourself, or are you going to cop out and ask the government to do it for you?
Here is the cost of basic income.
https://www.weforum.org/agenda/2017/07/the-cost-of-universal-basic-income-might-be-lower-than-you-think
Sounds like a nice plan, except it lacks choice.
You can put your money into a hat if you want. Just don't force other people to, by taxing them.
We may never know the cost because we can never see what will now not be able to be produced. The higher income earners are the ones that produce many of the goods you take for granted that will be available to buy with UBI payments. It those entrepreneurs who arrange capital goods and labor in ways that result in better and cheaper products for the consumer. And they are rewarded for their efforts with profit. If you hamper their ability to do so. We will never know the true cost of UBI, which is all the goods and services which will not be created as a result of it.
That's really the best you have? The cost will be zero because I will pay $12,000 and get $12,000 back in payments? Ludicrous. What's the point? Except to steal income from higher income earners, which is not an original plan at all..