Why are CDC's Covid-19 daily case count numbers so low?

A key measure for whether an epidemic is getting worse or better is "new cases per day". If that number is the same or lower than the previous day (regardless of the absolute number), the in theory the epidemic has reached the inflection point on its logistic curve. So I looked for case counts reported in this way (most headline graphs only show the accumulated total case count). I noticed the graph on the CDC's web site shows very low numbers[1] compared to another non-CDC site[2]. What's going on here? How am I misinterpreting the data?

[1] https://www.cdc.gov/coronavirus/2019-ncov/cases-in-us.html (under "Cases by date of onset").

[2] https://www.worldometers.info/coronavirus/country/us/ (under "Daily new cases").