Globally, central banks undertook monetary easing efforts in 2019 by the most since the 2008 financial crisis as shown in the chart below courtesy of the IMF.
This enabled unsustainable deficits, debts, businesses and financial Ponzis to continue a while longer and made the global economy and markets more correlated and vulnerable to inevitable shocks.
In reality, central bank balance sheets are tiny relative to the few hundred trillion in asset markets globally. And monetary placebos are only effective so long as they are believed. When the herd turns from manic to panic, central bank