If the Columbine shooting never happened, do you think there would be such thing as school shootings? Because thats what started it all

Bruh, this is America. We've had school shootings way before Columbine.

https://en.wikipedia.org/wiki/List_of_school_shootings_in_the_United_States_(before_2000)

No. As you said, Columbine is what started this trend