Science is probably not advanced enough to use this yet, but if a massively weakened strain of Covid was created, it could be modified to be much more transmissible. Then it would become the dominant variant and spread harmlessly around the world.
It would outcompete all other dangerous mutations and prevent them from getting any traction. (or for them to become worse mutations).
It could be a faster way to deal with plagues, instead of waiting for vaccines to be created in enough supply to end a pandemic globally.
If pandemics are the new normal (e.g. - a new cousin of Covid and SARS) - Viral Gain of function may be the only option.
Or a means to counter a lab-created biological weapon etc.


