The "reason" for QE was not for the banks to lend out all of their new funds. That would have caused inflationary pressures immediately. They did lend a fractio

The "reason" for QE was not for the banks to lend out all of their new funds. That would have caused inflationary pressures immediately. They did lend a fraction. That it was not a bigger fraction should tell you something about the perceived risks and risk appetite at the time. Recall the opening complaint was that the banks made easy money by lending cheaply obtained funds. If they could do that then there should have been no excess reserves. Both cannot be true. As for QE, increasing lending from reserves didn't turn out to be the only or even main channel of effect. Driving down yields was the main channel. In that sense it was indirect and inefficient for the amount of reserves injected, but not ineffective. In the end the spreads collapsed and money filtered out (not only from banks but from every holder of capital) from less risky investments to more risky investments, increasing the supply of capital to everyone. If you had to complain, it was that money took the longest time to reach the riskiest borrowers and that we're all on the hook for being front-run on Fed news (Fed paid more than they should to buy those bonds) [1]. That was unfair, not the rates that borrowers had to pay. [1] On the other hand, by pre-announcing, they probably needed to buy fewer bonds over all as the market moved itself on the Fed's credibility.