Sure, it only "just requires" it if you actually care about your program working properly in the presence of concurrency. To reiterate, this is as true in Rust as it is in C or Zig, it's just that also Rust allows you to do better than the "YOLO" approach to concurrency in a way that most languages could only dream of.

Seriously, I'm begging people to try writing a program that uses ordinary threads in Rust via `std::thread::scope`, it's eye-opening how lovely thread-based concurrency is when you have modern tools at your disposal.