The entire premise of the conversation is that other languages allow us to write idiomatic code and get good performance, and the parent's position was that Java requires "competent developers". So yes, the parent did say that, however...

> There's no such thing as a programming language that guarantees excellent performance regardless of programming competence.

No one made any claim remotely like this. This is a very obvious straw man argument. What was argued was that you can get decent performance from other languages without additional competence beyond idiomatic code.