Why was the ECB's reaction to COVID-19 crisis faster than after the 2008 financial crash?

At the time of the financial crises of 2008 and 2010–11 the ECB reacted with an extremely cautious gradualism. This behaviour is attributable to the slower learning process that characterizes a central bank of a monetary union composed of countries with fiscal sovereignty compared to other central banks. In sharp contrast to the previous crises, the ECB reacted promptly to the COVID-19 crisis. This change in behaviour is explained here by the learning process about the effects on monetary policy transmission of the increased financial fragmentation of the eurozone over the last decade