MS-13 isn’t even exceptionally violent so much as being surprisingly violent compared to its size, and that is pretty much a result of dumping an American gang into foreign gang territory and they had to meet like with like. You can throw a dart and hit a South or Central American gang that is insanely violent and organized on top of being funded and armed by the US. MS-13 is just the soup du jour.
I just find it especially irritating because in 2010 when Los Zetas terrorized Mexican tourism by dumping bodies on resort grounds and would massacre 193 people the next year to send a message almost no one I talked to knew anything about the cartels and gangs, but a few years later people were obsessed about the violent invasion from the south.