Because it is untrue:
https://www.ourquadcities.com/news/national-news/no-the-cdc-has-not-reduced-the-death-count-related-to-covid-19/#:~:text=WASHINGTON%20ā%C2%A0The%20U.S.%20Centers%20for%20Disease%20Control%20and,just%20over%209%2C000%2C%20as%20social%20media%20posts%20claimed.