Stock prices in the US don’t represent the economy. Something like 20% of the wealthiest people own 80% of the stock market. The reason they remain unaffected during covid is the rich are unaffected.

As you’ve mentioned, inflation rates impacts incomes differently. The stock market prices may be a measurement for the rich, but it’s not for most Americans. Our purchasing power is much different and inflation rates via the Big Mac Index is a way better representation of inflation for most people.