https://covidtracking.com/data/charts/us-currently-hospitalized
https://covidtracking.com/data/charts/us-daily-deaths
Comparing these two charts suggests that hospitalized mortality rate (deaths per hospitalized cases) declined by about 50% from the spring wave to the summer wave, but has not declined from the summer wave to the current fall wave.
I’ve been thinking hopefully that we’ve gotten much better at treating severe Covid, but that may not be true.
Ah, looks like you can overlay charts
https://covidtracking.com/data/charts/2-metrics-7-day-average-curves