I love Python for this. Big standard library. I hate JavaScript for this... So many weird legacy issues that generally get resolved with libraries. Though ES6 went a long long way.
ES6 does not fix the left-pad issue; there is a propensity to use a package to get one small function vs using a library of common helper functions (which is somewhat what e.g. ES6 helps with...less need for underscore or similar). You pretty much don't need jquery now, but so many things depend on it for convenience / backward compatibility / because it's so insanely battle-tested that you know that it will work or at least have a StackOverflow explaining why a particular thing does a thing in a weird way.
