The reason things look the way they do is certainly historical, but it's not developer's desire for great DX or user expactations - the later at least not directly - that drove us here. It's the requirements of enterprise processes that got us here. The popular stacks very much carry the mark of enterprise. BTW, you did this in Spring: another prime example of enterprise driving development process architecture. If you want to enhance that, you should focus more on requriments such as separation of concerns, developer replacibility, user tracking and marketing chances than UX and DX.