But with the topic at hand being social media, I think a lot of the same issues and solutions apply. It's harmful to allow kids to interact with anyone and everyone at any given time. Boundaries are healthy.
Aaaaand, finally there's much less destruction of human livelihood by guns than both of the aforementioned topics if we measure "destruction" by "living a significantly impoverished life from the standard of emotional and mental wellbeing". I doubt we could even get hard numbers on the number of marriages destroyed by pornography, which yield broken households, which yield countless emotional and mental problems.
So, no, guns aren't something we should discuss first. Also, guns have utility including but not limited to defending yourself and your family. Porn has absolutely zero utility, and social media is pretty damn close, but not zero utility.