It's tragic that only the threat of a deadly disease could compel such a change, but perhaps we may find other levers to help us achieve such widespread beneficial changes in the future?
A total shutdown of the entire world economy on an unprecedented scale still doesn't track enough to prevent climate change.
If that isn't a clear indicator of how severe the situation is then I don't know what else is.
The economy never came close to a “total shutdown.” In most places, the overwhelming majority of jobs were classified as essential—maybe 2/3rds—even while certain sectors did shut down. You can look at various stats, but a very simple one is the output gap, estimated to be 6%, which is potential GDP minus actual. This is a fair proxy for how shut down the economy was. The severe shutdowns were relatively brief.
Mostly, we massively changed the mix of activities we engage in, substituting relatively cleaner ones for more polluting ones. Maybe you purchased more manufactured goods and used more electricity, while driving less. A different conclusion from yours is that simple behavior changes—like more telework—can have significant impacts on emissions.
It proves that we can cut emissions without living a prehistoric lifestyle. And given that renewable energy sources are cheaper than polluting ones, this gives me reason to be optimistic.