[fallous]

I think the level of abstraction applied to "event" is key in determining whether the architecture is successful (or even appropriate).

If you attempt to implement at a granular level (got click on button!) then it turns into a giant mess because you're essentially reinventing the logical flow and event loop of programming via a message bus, which is a pretty terrible idea. If instead you operate at the business logic level of abstraction it can result in a much more coherent and easily-extended system, especially since that level also sees the most change from executives or operations. At that level it's also easier to integrate with third-party services.

It is certainly not a cure for all that ails you, despite the claims of some snake-oil salesmen to the contrary.