Talking about households is no longer UBI. If you want to talk about UBI, give numbers per person and then tell yourself if that proposed number could allow a single person to live in the Bay Area without working.
You’ve conveniently made an arbitrary division of 2.6 to hide the fact that a doubling would be required if UBI were truly universal, allowed people to quit working, and didn’t place restrictions on household status (as you just did).
That's not true. We have $10k tax revenue per capita, an average household size of 2.6, and the bar to get out of poverty for households of 1-4 is $12k-25k.
UBI would be a big cost but you could have an enormous impact with a program that increases the federal budget 50%. And if you set your break-even point to something like $80k of income then half that money is immediately recaptured in taxes, so now you only have to source 25% more money.