The amount of CPU time compiling code is usually negligible compared to CPU time at runtime. Your comparison only really works if you are comparing against something like Rust, where less bugs are introduced due to certain guarantees by the language.

Regarding “language constructs” it really depends on what you mean. For example using numpy in python is kind of cheating because numpy is implemented in C. However using something like the algorithm libraries in Rust woulf be considered fair game since they are likely written in Rust itself.

Not sure I understand your comment on multithreading. pthreads are not very hard to use, and you have stuff like OpenMP if you want some abstraction. What about C is not ideal for multithreading?

I remember easily getting gems for free. Also the streak basically doesn’t matter at all. What made me uninstall is the slow pace. It felt like I was stuck on the same words and topics forever. It felt like I was not actually learning anything, which if you’ve ever started learning a language if a formal setting, is very apparent.