Donald Trump completely ignored Birx and Faucci and did almost NOTHING either of them recommended. The White House changed CDC instructions and guidelines, and the CDC Director was a Donald Trump appointee with no experience in running an agency. We can lay the failure of the CDC to produce an accurate or efficient covid testing system right at his incompetent feet.
www.science.org
He also watered down CDC Guidance at the request of the White House:
The new guidelines provide brief checklists meant to help key businesses and others operating in public reopen safely.
www.politico.com
Redfield was criticized by former CDC Directors for his poor performance:
In a private, leaked letter, a former CDC director urges Dr. Robert Redfield to stand up for public health and stop the "slaughter" caused by COVID-19 in the U.S.
www.npr.org
We can safely assume from his history and record, that Redfield was appointed more for his "loyalty" to Trump than his qualifications and ability to do the job.