You can simply scroll down in this very comments section to find folks arguing about the performance characteristics of various languages in the context of making claims about their benefits. Res ipsa loquitur

That's simple indeed, but also simply wrong. Reality of actually written apps is a way more important factor than such comments, and in that reality the cult of performance is tiny, not crowding out everything else

My observation from internal C projects I’ve worked with is that they often end up doing the wrong thing very fast, because the right thing is so hard to express in C. If you do the wrong thing ten million times, it can start to approximate the right thing. The best of all worlds is using a low level language for speed and a high level language for dealing with complexity. I very much doubt there’s one right language for everything.