Both of those are deceptive comparisons: that page will tell you that China has had 90 fatalities in total since 2010 whereas despite being a third the size we have had 13,500 mass shooting deaths. Similarly, while the Bath bombing killed about a third more people than the deadliest school shooting (only ⅔ of the deadliest mass shooting) the difference is that you had to go back a century for that example whereas the shooting toll for any recent decade is higher.
The common factor is easy access to firearms. Every country has mentally ill people, every country has embittered people who are mad at the world, but only the United States has removed the restrictions on gun access which allow those people to engage in mass shootings. That started in the late 1970s and the contrast with our peers is staggering: Australia has many cultural similarities but they actually value life and tightened their gun control laws after the Port Arthur shooting, while we’ve loosened ours and have hundreds of thousands of more deaths.
Oh, aye? What's the record on mass decapitations at knifepoint?
And are you actually comparing a trained militia to randos buying military hardware without any accountability or oversight? Because generative AI isn't only accessible to trained and licensed practitioners, is it?
No they're not. The first reconized school shooting was in 1764, with the Enoch Brown school massacre. There have been school shootings ever since. (Unless you want to argue that the 1700s wasn't that long ago, which it also wasn't, but I don't think that's where you're coming from.)
Well, we're approaching the 25th anniversary of Columbine. But 35 years ago, my neighborhood was equipped with quite a lot of Uzis and Mac-11s, and we had quite a lot of mass shootings. Only they were called "drive-bys" and nobody circled the wagons to preserve the historical tradition of access to such equipment.
At what point did ordinary people get easy access to weapons that have high capacity and rapid fire? That's when we see a rise in mass shootings. Today, ordinary people are getting access to tools which can quickly and easily make better fakes than experts with photoshop could do even 5 years ago.
The deadliest school attack in US history was the Bath bombing, which did involve a gun, but most victims were not from it.
The common factor is mental health, not firearms.