Investigating viruses is normal procedure and has many advantages. Millions are spent investigating flu, common cold, mutations thereof, and other viruses every year. It's how we know how to deal with them, and how we can get better at making ways to counter them.
If this spill-out theory is correct, the Lab is at fault for improperly handling these viruses, something you can't really fault Fauci for. Unless, of course, you buy in and regurgitate political dribble.
The 12-letter furin, only found in the SARS-COV2 in humans, isn't in the Laos bat DNA that is closest to SARS-COV2, so it seems like it could be a smoking gun coming from the Wuhan lab due to this furin marker. Daszak, more than Fauci, seems to have been covering up by omitting obvious events or involvement, however, I am not sure Fauci doesn't carry any fault in what seems to be the carrying out of research that was not supposed to happen that inadvertently led to it making it into the human population.
And just common sense is at play here: Virus breaks out in Wuhan; the Wuhan virology lab that studies corona viruses is nearby; Daszak and the WHO seem to have went into coverup CYA mode; database is taken offline. At what point do people finally say this is the most likely scenario and there should be an investigation into how it happened to prevent it in future, mistake or not, gain-of-function or not, no matter how you define it.
The story isn't about 'investigating viruses', but (if true) about gain of function virus research meant to enhance their ability in order to study them.
It's noteworthy that all the research which helped with COVID so far had nothing to do with GoF research or the Lab. The spike research dates back to SARS-COV-1 studies. The vaccine technologies used had little to do with GoF. On the other hand, the Wuhan Lab, supposedly experienced with coronaviruses, has apparently gave us nothing useful to combat the pandemic.
Apparently the Wuhan Lab's research was dangerous (this is true even if this thesis is not) yet also useless.
While Fauci oversaw funding the gain of function through an intermediary to avoid Obama's prohibition against this dangerous research, I'm not sure why you brought in Fauci. You could also mention Fauci oversight of funding dog torture to study beagles being eaten alive by sand fleas, according to PETA.
https://www.peta.org/blog/fauci-niaid-puppies-animal-testing...
If this spill-out theory is correct, the Lab is at fault for improperly handling these viruses, something you can't really fault Fauci for. Unless, of course, you buy in and regurgitate political dribble.