I think the public school system is failing in so many ways and homeschooling is a better solution, but even with that, school shootings are near the absolute bottom of my concerns. They're an issue, but we have so many more pressing issues that are hurting kids so much more. The shootings are so heavily promoted on the news because engagement is good, clicks make money. Keeping people scared is profitable.
Most of those recorded "school shootings" are simply cases where a gun was fired on school grounds, not a "mass shooting". In literally almost every single case, it's one kid shooting another kid an is gang-related. You can actually go through and see the exact circumstances around each incident, along with a pertaining news article:
https://www.edweek.org/leadership/school-shootings-this-year...
So hopefully that gives you a little bit of comfort! As long as your kids aren't violent teen gang members in the school parking lot after a football game, it's highly unlikely that they'll even know someone who has witnessed gun violence at any school.