Because they're anything but actual experts. Or, if they do actually happen to be experts in their field, they abandon their expertise in favor of whatever will get them political power.
Some of those first 40,000 dead would have died due to lack of knowledge of how to mitigate the risk and treat vulnerable people. That sucks but was unavoidable since we did not know which pharmaceutical and nutritional agents were effective.
95% of the rest, and 95% of those who get the virus and die today are doing so as a direct result of intentional actions by State Governors, the President of the United States both past and present, the CDC, the NIH and every single so-called "public health" institution including the hospitals, teaching and research universities including but not limited to IHME, Vanderbilt, Johns Hopkins and countless more.
No matter how bad you think the government is, it's worse. Far worse.
Our government -- including Federal, State and Local officials, in concert with both the medical system and our alleged "public health" agencies deliberately spread disease and caused death for the last year, directly and through depraved indifference, killing approximately 400,000 Americans thus far and is killing thousands more every single day. We knew how to stop the death in nursing homes in February of 2020 and we knew how to stop 95% of the deaths in the general population this summer using cheap and available nutritional supplements and off-patent medications. Rather than fulfill their legal duty both by their oaths of office and in the case of non-profits and public health organizations the duties set forth in their charter and the reason for their tax exemptions they instead conspired with commercial interests to allow and even promote such death so as to inculcate fear in the population for the purpose of political, ideological and financial gain.
Do I think the government allowed people to die in order to get Orange Man Bad out of office? Yes. I also think that there were parts of the government that were too stupid and ignorant to read anything about the success stories regarding this virus, and how to duplicate them. I also think that portions of the government are so ideologically blinded that if their God, Dr. Fauci, flip-flopped yet again and said that they all need to drink camel urine to prevent the Kung Flu, they would be on a plane to the Middle East to get it straight from the source.
At best - and I do mean the absolute best case scenario, our government was so worthless and stupid that it allowed hundreds of thousands of people to die because they couldn't figure out what when doctors used Ivermectin or Hydroxychloriquine and it worked, you should give that a try. That's the absolute best case scenario - complete and utter incompetence.
But I don't think they're that incompetent.