There's no "find usages" for events, and it becomes harder to find out why something didn't happen. A function call can't simply "not return" - in the worst case you get an exception, or a stuck thread in the caller that will show up in a stack dump. But downstream event processing can very easily just not happen, for one of many different reasons, and out-of-the-box it's often difficult to investigate.
Remember "callback hell"? Assumption that a function call returns after running to completion requires rather specific synchronous cascading architecture, which WILL break in multithreaded code. Most of the multithreaded function calls will set a flag in shared memory and return early, expecting caller to poll.
If your API is based on single entry-point `invokeMethod(callee, method)` it is equally untraceable to event entry point `fireEvent(producer, event)`.
The problems you describe are inherent to indirect invocations and are related to event-driven architectures only because typical event dispatching architecture is built on non-blocking calls.
You do not even need return-early (non-blocking) semantics for these problems to manifest. You can implement a giant string-keyed vtable for all methods in your program (or use a language with advanced reflection capabilities) and will have exactly the same problems. Namely there probably won't be tooling to match caller-callee pairs, which is the core issue here.
Yeah, good luck remembering to do that up-front for every event handler. You missed one? Whoops, enjoy the information you wanted silently not being there when you need it.
Remembering to do what? Properly maintain a list of constants and enums to use throughout my application?
That's not something I have to remember or forget, it's a simple habit that is as natural as importing and referencing a function.
As a general rule, numbers and string literals should never be hardcoded. Internalizing this should be a base expectation of any high-performing team member.
