Twist, Zerp and the series of QE's are all of the "Quantitative Easing" stimuli that the US Federal Reserve have used in their "attempt" to stimluate the economy. They have been unsuccessful.
As far as welfare is concerned, I don't think I could say it any better than Milton Friedman.
QE isn't the same as a UBI. A lot of QE wasn't spent into the economy. And I'm not sure how much evidence Milton can produce from the 1970's.
Yes, the vast majority of the "stimulus" money is still in the hands of the banks. In terms of stimulating an economy, it would have been more effective to simply give people people "helicopter money". Instead it was given to the criminals that caused the problems in order to prop up their failing banks by the unelected and unaccountable controllers of the money supply, the central banks. I don't believe the intent was anything more than that, keep their friends out of jail.
As far as welfare goes, there's a vast amount of evidence, over 50 years worth, that shows the negative effects of paying people not to work. Drive through the slums of Detroit or Chicago some day if you'd like to see the real effects of welfare.