Back when I first took undergrad economics, there was "micro" and "macro". And since then there has been much work to try to integrate these. But the original Keynes denies the workings of the price system. Robert Higgs explains how this is so in this delightful essay.
Read it and see how and why the Keynsian policies being mounted to make things better are most likely to make things worse. Recovery will, therefore, be in spite of policies than because of them.
But that same debate is still going on re New Deal policies. That ground is covered here, among other places.
The famous cover graphic of Charles I. Jones textbook suggests that we will somehow revert to the same growth path. Institutions trump policies.