Unfortunately, due to the political situation in the country, it's currently impossible to do the one thing that we know might actually stop those shootings (make it harder or impossible for people, especially children, to get their hands on heavy weaponry). So by the "logic" of "we must do something" "this is something" "then we must do this", we have active shooter drills instead.
The best solution I see is worldwide disarmament in some manner that still allows equalization of women, elderly, etc in physical force. That's a pretty tall order honestly not sure that happens anytime in my lifetime. It also has a sort of 'prisoner dilemma' element where the individual would be insane to give up their arms while the criminal still has theirs.
Advocates of "gun control" in the US don't realize this part, they seem to assume by making guns less available the criminals won't be able to find them.
As the comment above you says, they’re between counterproductive and unnecessary, and purely creatures of posturing and appeasing scared parents.