Plenty of people say C is fast . I think C is faster than other languages in the same way that a shopping cart is safer than a Ferrari.
Yes, a shopping cart is safer.
… but it’s because it makes it so hard to do anything dangerous in it, not because it’s inherently safe.
I wouldn’t feel comfortable in my shopping cart rattling around a Ferrari race track at 150 mph, because I’d be acutely aware of how fast the tarmac is blazing past my feet and how inadequate my tools are to handle things that might go wrong. I would probably feel the same way if I could step through the inner workings of a moderate Python program through the lens of C decompiler.
To put it another way: almost everything that makes a program in language XYZ slower than one in C probably uses a feature which could you could have synthesized manually in C (as a design pattern instead of a language feature), but that you chose not to simply because it would have taken you painfully long to do so.
I bet that you could probably write C-like code in almost any language, and it would probably run at least as fast (with a reasonable optimizer). You could also drive a Ferrari as slow as a shopping cart and it would be at least as safe. But why would you?
 299 792 458 m/s