Sure, income inequality and poverty are drivers of all forms of crime. And the US in addition to uniquely lax gun restrictions also has uniquely terrible social support.
But if you look at the above article you’ll see this:
Even so, the child firearm mortality rate in the U.S. (3.7 per 100,000 people ages 1-17) is 5.5 times the child and teen mortality rate in Canada (0.6 per 100,000 people ages 1-19).
Guns kill children in the US at a rate 5.5 times higher than all causes of child death in Canada. And it is our closest peer, in other wealthy countries this would be even more lopsided. We can talk about why that is, and there are many reasons including social inequalities, but if you’re not considering access to guns a driver of gun deaths plus the abundance of published scientific evidence that supports this, you’re not approaching this issue honestly.