God fucking damnit stop doing that people (Not you, the creators of new fallout media). Fallout since Bethesda took over has just refused to move on from stuff. Fallout and Fallout 2 made it quite clear that super mutants were a thing that happened once, it was a result of the FEV project and the FEV project is doneso with the Master’s death. They had a whole thing where the Super Mutants were both resigned to being a dying race and nostalgic for the time they almost conquered the world, and in New Vegas they are the focal point of themes about letting go of a world in which you no longer fit in and having to consider your impact in terms of legacy. The principal Mutant characters are either senile, or resigned to fading away (Or their arc concerns becoming okay with doing so).
Then in Bethesda fallout they’re fucking mass produced orcs who were always around, will always be around and can just super easily be made.