Yup. You get it. The solution is simple, with one exception. Simple doesn't mean easy.

We need socialized healthcare including mental healthcare. That would do a lot, there are almost always signs that a non-gang mass shooter is mentally unwell.

Gang and crime based mass shootings would fall through the floor if we removed the incentive for them, prohibition of drugs. Addiction should be treated as a health problem.

We need to identify these sources of hateful propaganda, the nests of poisonous ideology and root them out through education. We aren't teaching critical thinking, I think that also has a lot to do with it.

You also have many young men that lack good role models for positive masculinity. This is a big thing I'm not sure how to fix. Toxic masculinity has become so pervasive and has infected almost every straight man that can be considered macho. I'm a very masculine man, and proud of it. My zippo says Daddy. My straw hat also has a pride/equality pin next to a Ruger pin. The number of men that I meet like myself is quite low. Met a very macho trans man once that I found had a similar worldview. Have met similar men in the gay leather communities but they tend to cluster in large cities and form insular communities for their own safety.