Well in the last seasons before expansion (S28-S30), 3 of 4 European teams were so bad that we implemented crossover. But even then, Davos was still one of the top 4-5 teams, so it's not like NA was guaranteed to win every season (even though NA did win all 3, including a SEA/NY and SEA/CGY final).
If you add in the record-breaking Quebec streak and Toronto still being better and NY not being slouches themselves, well, yeah, it's pretty unique all things considered.