Slackware. Installed from 3.5" floppy disk.

C and Rust are low level languages, suitable for interacting directly with the hardware. C++ might be described as C with some object oriented stuff bolted on, making it excellent for videogame development. C# is a lot more like Java. It’s great for line of business apps because it handles the complexity of memory management for you and provides an excellent framework and excellent libraries for a lot of common tasks. But it’s not suitable for low level work.

The main improvement Rust provides is memory safety. It’s very easy to make mistakes in C where you could overrun a buffer or something, introducing unexpected crashing and making it vulnerable to exploitation by malware or whatever. Rust eliminates a whole category of issues with their clever memory management paradigm. The improvements in this schedule probably have more to do with the strategy used than code efficiency.