So he puts polymorphic function calls into enormous loops to simulate a heavy load with a huge amount of data to conclude "we have 20x loss in performance everywhere"? He is either a huge troll or he has a typical fallacy of premature optimization: if we would call this virtual method 1 billion times we will lose hours per day, but if we optimize it will take less than a second! The real situation: a virtual method is called only a few hundred times and is barely visible in profiling tools.
No one is working with a huge amount of data in big loops using virtual methods to take every element out of a huge dataset like he is showing. That's a false pre-position he is trying to debunk. Polymorphic classes/structs are used to represent some business logic of applications or structured data with a few hundred such objects that keep some states and a small amount of other data so they are never involved in intensive computations as he shows. In real projects, such "horrible" polymorphic calls never pop up under profiling and usually occupy a fraction of a percent overall.
No one is working with a huge amount of data in big loops using virtual methods to take every element out of a huge dataset like he is showing. That's a false pre-position he is trying to debunk. Polymorphic classes/structs are used to represent some business logic of applications or structured data with a few hundred such objects that keep some states and a small amount of other data so they are never involved in intensive computations as he shows. In real projects, such "horrible" polymorphic calls never pop up under profiling and usually occupy a fraction of a percent overall.