All of these are instances of doing something _wasteful_, which is the #1 issue he mentions in the list of things that cause performance degradation.

Now, your argument seems to be: in the real world, there's so much waste, that virtual function calls pale in comparison.

This does not debunk his main point, which seems to me at least the following: all things being equal, writing code with virtual functions that do a tiny amount of work and "hiding implementation details" makes performance worse, sometimes by an order of magnitude.

Now, there maybe situations where you _have_ to use virtual functions, because you are writing a library for other people to use, and you can't dictate ahead of time how they will use it.

This again does not invalidate the point. You need to be _aware_ of the performance implications of this, and mitigate it. He said the following in the comment section on the article:

> Try to make it so that you do very rare virtual function calls, behind which you do a _large_ amount of work, rather than the "clean" code way of using lots of little function calls.