And the data for the two decades before that should be tossed out because of the global housing crisis, the sovereign debt crisis, and all the reverberations from that.

And the data for the two decades before that obviously needs to be tossed out because of the one-off nature of the dot-com boom, the dot-com crash, 9/11, and so on.

And before that... point is, you don't get clean data in economics. There's always something big going on, there are no double-blind trials to run, etc. It's called the dismal science for a reason. But that doesn't make it useless.

If your only dataset is 2008 to 2010, yeah your conclusions are almost certainly garbage. Likewise if your dataset is 1999 to 2002, or just the year 1987.

There will always be something going on, but there won't always be this specific thing going on, and if 100% of your data comes from during one specific crisis (nonetheless multiple concurrent crises), then it is 100% useless. Even with longer periods of data, reconcilliation with longer trends is technically challenging. We've had enough recessions to correct for them in our data, but until we've had a half dozen global pandemics you can't use pandemic data in your analysis.