I think headers were a great tool from a time before intellisense where developers and teams would include function + comments on how to use it. On the flip si

I think headers were a great tool from a time before intellisense where developers and teams would include function + comments on how to use it. On the flip side, I think there are still a lot of developers who don't use language servers or use the equivalent of notepad who do rely on separate header files as a means of documentation. That said, it's always been painful to structure inter-related headers and source files to avoid circular dependencies, and if modules truly resolves that, I'm happy to see it.