It's the only language existing that is memory safe and provides zero cost abstraction to the CPU capabilities (i.e. no mandatory GC, values don't need to be boxed, ability to mutate memory).
The only limitation that may not eventually be removed is the lack of dependent types (although you can kind of emulate them by lifting terms to the type level and using lifetimes to represent variables).
C++ is not memory safe, Lisp has no type system and Haskell has GC, all values are boxed in a closure and it cannot mutate memory safely, so none of these languages are even in contention.
The only limitation that may not eventually be removed is the lack of dependent types (although you can kind of emulate them by lifting terms to the type level and using lifetimes to represent variables).
C++ is not memory safe, Lisp has no type system and Haskell has GC, all values are boxed in a closure and it cannot mutate memory safely, so none of these languages are even in contention.