I'm not sure what this comment is implying. The author isn't complaining about Python's performance, rather, it's noting that concurrency in Python isn't as painless as it is in Rust (which isn't a controversial statement, Rust is explicitly designed for robust concurrency). It also isn't controversial that Rust code should end up faster than Python, considering that Rust is designed to prioritize runtime performance. This isn't a case of comparing the performance of two dynamic languages (as we so often had with all the "I switched to Ruby" or "I switched to Node" posts in prior years); nobody is going to hold up this blog post as proof that Rust is generally faster than Python, because nobody in the world argues otherwise (and I say this as a prolific Python user, not just as a Rust user).