You’re right: Aurelia can avoid a build step and still preserve flexibility, and the kind of helper you sketched (load_modules("thispage")) would definitely make the default case much less verbose while still allowing people to override pieces explicitly when they need to.
With dagger.js the initial choice was to keep everything explicit to reinforce the “HTML/JS/CSS are just independent modules” idea, but I agree that adding a convention-based shortcut on top could make the developer experience smoother without removing transparency.
In future iterations, I plan to add more flexible usage patterns to better meet diverse development needs.