I almost mentioned Go as another example of what it doesn't substitute for, but decided to cut off the list. But no, I don't think it fits that niche either. Go has a lot of features D doesn't have. Just off the top of my head: it's very simple, it doesn't have pointer arithmetic (yes, that's a feature here), it performs escape analysis to automatically extend the lifetime of objects that escape the stack frame, etc.

D does not allow pointer arithmetic in code marked @safe.

D does escape analysis from an alternative direction. If a pointer is qualified with `scope`, the compiler guarantees it does not escape the stack frame.

I'm well aware of those, and they obviously don't fill the gaps here.

Well that shouldn't be a mystery. Golang was marketed by Google.