In this specific case, yes those particularly would be an example.
But I don't mean in comparison to other languages or frameworks, I mean in generally, as in, I'd avoid creating syntax extensions or using them in any project.
i understand your argument but if you look at <https://news.ycombinator.com/item?id=13246361>, it seems clear to me the use of syntax extensions created an awesome developer experience that would be otherwise impossible (sure you could use the built in typesystem but then you wouldn't have human readable routes in the source)