indeed, it's a matter of juggling competing maintainability considerations and there are cases where it can make sense to couple components tightly.
that said, in practice our UIs contain relatively few one-off components, and it often requires less dev friction simply to use the standard event pattern than to weigh borderline cases to shave off a little indirection at the cost of tighter coupling. the problem of "too many events in the system" is avoided by letting complicated components handle events from their own subviews and not just blindly bounce everything down to a global mediator. e.g. if no other views have to know about the 4 dropdowns and slider within MyWidget (and they usually don't), then MyWidget can handle all those subview events itself and simply present a single unified 'i've been updated' event for other consumers. essentially narrow the public apis between different actors in the overall system.
that said, in practice our UIs contain relatively few one-off components, and it often requires less dev friction simply to use the standard event pattern than to weigh borderline cases to shave off a little indirection at the cost of tighter coupling. the problem of "too many events in the system" is avoided by letting complicated components handle events from their own subviews and not just blindly bounce everything down to a global mediator. e.g. if no other views have to know about the 4 dropdowns and slider within MyWidget (and they usually don't), then MyWidget can handle all those subview events itself and simply present a single unified 'i've been updated' event for other consumers. essentially narrow the public apis between different actors in the overall system.