Ben Bernanke has studied and written [0] extensively about this topic; a copy of a speech he delivered at Washington and Lee University in 2004 can be found at [1] for those interested. 0: https://www.nber.org/system/files/chapters/c11482/c11482.pdf 1: https://www.bis.org/review/r040305e.pdf
I believe the implementation of this concept via the Fed (bank of banks) is the real issue. Basically, liquidity goes to the banks. Anyone having a relationship with banks gets access to this liquidity and benefits. Of course, we plow these "gains" back into assets (hard or stock market), this drives up prices, and we get asset inflation. For the person renting an apartment, leasing a car, and with credit card debt ... well, they lose. The trickle down doesn't work. You can interpolate and extrapolate from this brief comment, and I believe that this is the fundamental source of the expanding rich/poor divide.