All the various non-conventional measures that central banks, including the ECB, have taken over the last years have been directed at avoiding a financial and economic collapse. That collapse has not materialized. The relevant issue now is the timing and speed of the exit from these measures.
This will have to be guided, on the one hand, by the need to maintain support for the orderly functioning of the money and financial markets and to sustain credit flows to the economy, and, on the other hand, by the need to avoid introducing distortions into the system and sowing the seeds of future imbalances.