The language is rarely a hurdle. The (almost always bad and broken) tools, the (often misleading, as far as best-practices go, or muddled with old versions and outdated advice) documentation, and learning the culture and ecosystem ("Oh no, no-one uses that built in function since it's bad for reasons X and Y, use this 3rd party FOSS library entirely supported by one guy living in a cabin in Wyoming instead") are what make it difficult.

The language itself is often no trouble at all. It's all the stuff around it that ends up eating shitloads of time.