We don’t have a school shooting problem. We have a perception of scale problem. There are roughly 15 million high schoolers in the US at any given time. What percentage of them are actually engaging in school shootings? It’s less than 1/10,000 of 1 percent.
High schoolers are more likely to be killed by a wasp sting than by a school shooter. It’s not guns, it’s not video games. It’s just basic probability when you are dealing with millions of people. A few of them will decide to kill others.
Attempting to reduce the number to zero would require a level of micromanagement and infringement that would do more harm than good. You can’t preemptively prevent every crime without stripping away every remaining remnant of human liberty.