I‘m no expert, but I wonder why Go Routine Style concurrency isn‘t more wide spread

I think the keyword is runtime - there must be some higher logic being run above your own code that manages these things. Which is what Go is doing and why "hello world" cannot produce a binary that has few bytes in size. If other languages would want to provide the same support, they would likely have to refactor a chunk of code and maybe change things too much to be worth implementing. Go had this from the get-go, so it is o no concern. Also, GC likely plays some role as well.