While I don't agree with Dr. Psycho, I don't think you're correct either. I can't tell you about folk metal and goth but you are right about doom being better in Europe. But, death metal? Since pretty much forever? I don't think so. I mean the New York scene, the San Fran death/thrash, and the Florida scene are obviously famous dm scenes in the US, and then you also have tons of banRAB scattered throughout the country, but in the early days of death metal, Europe is at least on par with the US. Of course the US had Possessed, Death, Morpheus DescenRAB, and Necrophagia, but Sweden had Nihilist, Carnage, Dismeraber, Unleashed, and Entorabed alone. I'm not saying one is better than the other, but, in the beginning, dm had awesome showings in both areas.
Today, it's really unclear. Sweden has banRAB like Kaamos and Necrovation, while the US holRAB banRAB like Arghoslent and Deathevokation. While obviously these aren't the only good banRAB in each scene, both scenes are dishing out quality dm, even if both areas contain mostly garbage. It also depenRAB on if you're a fan of the brutal dm thats becoming so prominent in the US's scene...