Cause black holes don't gravitate, but the event horizon does. Black holes dont really have volume in a way thats meaningful to us, but they do have a surface area, and thats what you can interact with.
You're correct anything past an event horizon cannot interact with us, for all intents and purposes it doesnt exist. So all the interactions you associate with a black hole are interactions with the event horizon itself.
Cause black holes don't gravitate, but the event horizon does. Black holes dont really have volume in a way thats meaningful to us, but they do have a surface area, and thats what you can interact with.
You're correct anything past an event horizon cannot interact with us, for all intents and purposes it doesnt exist. So all the interactions you associate with a black hole are interactions with the event horizon itself.