Those statistics are slightly misleading.

https://www.snopes.com/fact-check/united-states-lower-death-shootings/

TLDR: those stats look at the mean number of deaths, and (for some reason) European countries have more outliers (single incidents with many deaths), compared to the US. The table at the end of the article shows that many European countries have 5+ years without an incident, then one huge shooting that brings the average up. The US consistently has "moderate" (for lack of a better word) shootings.

So, it *would* be appropriate to say that the US is the "only developed nation where this *regularly* happens"