For instance Go was designed based on SCP (notably), a theoretical language designed by Tony Hoare in 1978 which implements a workable and fairly efficient concurrent paradigm. At the compiler then runtime level (low-level things you'll never be able to 'change' with libraries), when the program is built then executed, the implementation is directly able to translate into the physical topology of multi-core machines (Go design began in the late 2000's, shortly after Intel released the Core Duo, first multi-core CPU).
Now you can do parallel and/or concurrent in other languages, of course, but since they were not designed as such, it's a convoluted programming exercise to say the least. For proof, observe how little software is able to multi-thread efficiently today, how very little is built in a concurrent approach — it's just a mess in most languages, the added complexity not worth the cost.
This is an example of how you can get the functionality of a fundamental feature but the cost, the implementation curve is so steep that it doesn't really fly — reality, money, skill pool, all these things.
On topic, functional languages like Haskell do indeed "fix" or rather implement some features in more efficient ways than e.g. Python; it's always a trade off you know. No best tool, only tools best suited to a given case.