I've lived my whole life in the USA and never once been in or around a shooting, let alone a mass shooting Only time I ever experienced a mass shooting was in the Netherlands.
But yea, I totally agree, they are absolutely preventable, exceedingly rare, more rare than lightening strikes but preventable. I never said anything to suggest they are. IF the USA had even a fraction of the mental health access and education most of Europe has shootings would be nearly non existent. By all means we should get those things and end shootings.
That said, the point still stands, if you are living in fear of shootings when they are half as common as being struck by lightening, then your fear is directed in the wrong places.