In case you don't know, gain of function research is a type of research conducted on viruses where they give a virus functionality or inability it didn't have before. This is done by cutting and splicing parts of other viruses and combining different viruses together and mutating them to eventually produce any virus with new abilities that didn't previously exist.
If you're thinking that this sounds dangerous, you would be correct. Rational scientists have objected to this type of research because of the risks it poses. You are purposefully designing viruses that can do more, and usually that means making them more dangerous. But the other camp of mad scientists doesn't care and just wants to create more deadly strains. The justification is to find a way to combat these deadly strains that they created.
Those who support this are idiots in my book. Because the justification is to defend against something that wouldn't even exist if you want creating it. So why create these deadlier strains in order to find a way to combat them. All you have to do is not create them in the first place.
In a 2012 paper, Dr. Fauci is one of these lunatics who thinks the advantages outweigh the risks:
In an unlikely but conceivable turn of events, what if that scientist becomes infected with the virus, which leads to an outbreak and ultimately triggers a pandemic? Many ask reasonable questions: given the possibility of such a scenario—however remote—should the initial experiments have been performed and/or published in the first place, and what were the processes involved in this decision?
Scientists working in this field might say—as indeed I have said—that the benefits of such experiments and the resulting knowledge outweigh the risks. It is more likely that a pandemic would occur in nature, and the need to stay ahead of such a threat is a primary reason for performing an experiment that might appear to be risky.
There you have it. The logic is faulty. If a pandemic would emerge, and you really want to find a way to protect yourself against a virus, and work with the actual viruses you have. The will creating new ones that are more violent and more deadly and claim the alleged benefits are worth the risk of it getting out. Most likely this is what happened with COVID-19.