Earlier quoted context omitted.
Reserves have nothing to do with the amount of bank lending. Only the price of such lending. https://onlinelibrary.wiley.com/doi/abs/10.1111/pbaf.12249
Doesn't reducing the price of lending tend to lead to more lending?
Theoretically, yes. If loans are 2% instead of 4% then that may induce people to take one up to do some kind of economic activity (start business, renovate house, buy a new car, etc).
But it is not guarantee: people may feel too financial vulnerable to take risks with borrowed money. This is where the limits of monetary policy are run it.
There are points where the government starts spending on various projects: if a contractor is hired to build a bridge, and it will take "x" years, then all of its employees may feel more confident and do more spending because for the next "x" years they're set. Their money then goes into other people's pockets, into other people's pockets, etc.
Public/government spending to kickstart demand is what Keynesian economics basically is.