In languages like JavaScript, you have to be careful to avoid blocking the event loop, and use something like worker threads for CPU-intensive tasks. Otherwise you will end up with long tail latencies. In Go, the runtime automatically manages this and can suspend and resume long-running goroutines.

> naively accessing a global value can lead to race conditions

Fair point that the language doesn't automatically catch this, but that's what a mutex is for. In return you get actual parallelism that can use all your CPU cores