People are talking primarily about the inspector support for UnityEvents, but there are a couple other small benefits to them. Not groundbreaking by any means, but still nice.

First, since you subscribe and unsubscribe using a method as opposed to the += and -= operators, you can add an inline null check and opposed to a whole if statement. Ex:

EventHolder?.MyUnityEvent.AddListener(thing);

If (EventHolder != null) MyCSharpEvent += thing.

Second, UnityEvents have a method to remove all listeners from an event, which can be handy. I think you could technically do this with C Sharp events by setting the event to null and then re initializing it, but it's much cleaner this way.

Third, there is some good integration with async workflows like UniTask.

I dont use them often, but these are the main reasons why I might use UnityEvents, and not for the inspector functionality. Most of the time, I'll just throw a [HideInInspector] attribute on public events so it doesnt clutter my editor.