[throwaway894345]

I don't think it's that the fabs were shut down because of covid, but rather because automotive manufacturers (and presumably others) forecasted record low sales for 2020 and canceled all of their chip orders such that chip suppliers and upstream fabs had to lay off staff and so on. As I understand it, this was what reduced fab capacity, not "fabs were closing to avoid the risk of covid".

On the flip side, rather than demand decreasing as auto manufacturers expected, it actually spiked, and automotive manufacturers demanded more chips and were willing to pay $$$ for it. So other industries that use chips and accurately forecasted their demand were now bidding against automotive manufacturers for that fab capacity.

[brendoelfrendo]

Auto makers and others are part of the problems with forecasted demand, but there are also larger supply chain issues. Basically every part of the industry, going back to raw materials, is having similar shortages; either because people shut down for COVID or because they, too, underestimated demand during the pandemic.

[throwaway894345]

I suspect it has a lot more to do with failing to properly forecast in general, whether overestimation or underestimation. Supply chains are finely tuned for life as usual and they take a long time to recalibrate.