This is common piece of received wisdom, but I don't think it's held up well over the last decade: both Java and C# have extremely well-optimized runtimes that perform admirably after an initial startup period, and (I believe) Swift compiles to native code with many of the same optimization advantages that Rust has (e.g., simpler alias analysis).

At the same time, C++ has seen a proliferation of patterns that are slightly safer, but perform miserably at scale: smart pointers (unnecessary lock contention), lambdas (code bloat, more I$ pressure), templates (I$), &c. C avoids most of these, but C written by "clever" programmers has similar pitfalls.