The "beaks instead of teeth" might explain an advantage birds had, but why did all the other many and varied dinosaur species go extinct while lots of other thi

The "beaks instead of teeth" might explain an advantage birds had, but why did all the other many and varied dinosaur species go extinct while lots of other things with teeth (mammals, fish, reptiles, amphibians) survive? As the original paper ( https://www.cell.com/current-biology/fulltext/S0960-9822(16)30249-4 https://www.cell.com/current-biology/fulltext/S0960-9822(16)... ) says it suggests is a key trait, but its not the whole story?