You have a very fundamental misunderstanding that is making you create a distinction that doesn't actually exist. There is no "non-blocking use case". The use

You have a very fundamental misunderstanding that is making you create a distinction that doesn't actually exist. There is no "non-blocking use case". The use case is web development. You absolutely do not need to use event loops to write UIs, or anything else. You should never have to write event driven callback spaghetti, just like you should never have to write direct jumps (goto). Reasonable languages provide actual concurrency constructs, allowing you to write simple, easy to understand code, while providing all the benefits of both threads and event loops. Traditionally you needed to use a good language like haskell or erlang to get this, and that caused problems for people who want to stick with primitive languages. Now go has come along and offers similar benefits in a primitive package, so there is no need for people to have to stick with low level, error prone event loops.