Most third world countries don't have a problem with mass shootings, but the US isn't the only first world country that has had mass shootings.

I'm not sure I could name a single country with as many shootings per capita as the USA.

Not in the top ten. All ten are neighbors though.

https://worldpopulationreview.com/country-rankings/gun-death...

(Ignore Greenland. Tiny population with some gun suicides make it an outlier. You’re not going to get shot by someone else in Greenland)