Then it isn't UBI. By definition, you get exactly the same amount as everybody else, regardless of their income from whatever source. This means that you're always better off if you take a job.

Putting “this is human nature” as the full stop explanation tells me nothing and convinces me of nothing. How is Alaska’s UBI deducted based on income? That just isn’t how UBI works and not what UBI is. Same with your statement that it will be for “only certain approved things” which is not UBI, but means tested assistance, which as I said, comes with huge monetary waste in paying people to define what is “approved”, developing mechanisms on how it will be tracked, on businesses to implement systems, and on people to monitor compliance.

UBI is basically a tax credit. If you are poor enough that you pay less taxes than the UBI, you get a tax rebate. If you pay more, you get the money in the form of less tax obligation. The US already spends $1.101 trillion on welfare programs, a significant portion of that is wasted in the massive bureaucracy needed to oversee means tested assistance. If it was a simple tax credit with no overhead, that would be over $4,000 per adult per year.

“those on UBI” shows that you are not talking about UBI, because UBI is universal. Elon Musk would get UBI and pay $12,000 less on his taxes, and the single mother working at McDonalds would also pay $12,000 less on her taxes, likely resulting in a tax rebate check. To reiterate, it is literally just a dividend paid for being a “shareholder” of the company that is the United Sates (or whatever other country).