Pizza rat was still fairly niche. From my personal memories, the "global unified virality" peaked with Ice Bucket Challenge, Gangnam Style and maybe Harlem Shak

Pizza rat was still fairly niche. From my personal memories, the "global unified virality" peaked with Ice Bucket Challenge, Gangnam Style and maybe Harlem Shake. I have a feeling as recommendation algorithms became more prominent, it started to silo every "trend" rather than showing "most viewed things" to the people.