We're not talking about random changes. We're talking about paying attention to the measured performance of changes made for other reasons.
Just like in this article. The author measured, wondered, investigated, experimented, and finally, after a lot of hard work, made the C/Rust programs faster. You wouldn't call that luck, would you? If there had been a similar performance regression in CPython, then a benchmark could have picked up on it, and the CPython developers would then have done the same.
