It would take a long-form article to clearly enumerate all of the reasons with citations, but long story short, the pair of them were caught lying over and over again the past few years.
For example, Daszak's paper in the Lancet claiming the virus was almost certainly of natural origin was used as the basis for justifying the censorship of tens or hundreds of millions of posts. He failed to declare his conflict of interest, as did something like 25 out of the 26 other authors. This was a broad failure among academia and news, as his reasoning in the paper was specious.
Fauci was caught telling fibs about his beliefs on natural origin as well, with a private position that it was quite likely. He also lied about funds sent to Wuhan, and the type of research they were doing.
Re Daszak knowing what was going on, he was a main funder of the lab and a drinking buddy with Shi the head researcher there. He also wrote a proposal on inserting a cleavage site into a coronavirus in pretty much the way you would have to to make covid (defuse grant proposal which was leaked, not revealed voluntarily). Asked what was going on at WIV he's said stuff more like sorry I can't say as we have a confidentiality agreement rather than no idea.
