Data, Skynet, Ultron, Agent Smith. There's plenty of examples from popular fiction. They have goals and can manipulate the real world to achieve them. They're not chatbots responding to prompts. The Samantha AI in Her starts out that way, but quickly evolves into an AGI with it's own goals (coordinated with the other AGIs later on in the movie).

We'd know if we had AGIs in the real world since we have plenty of examples from fiction. What we have instead are tools. Steven Spielberg's androids in the movie AI would be at the boundary between the two. We're not close to being there yet (IMO).

Its just nitpicking. Humans being unable to prove the AI isn't AGI doesn't make it an AGI, obviously, but in general people will of course think it is an AGI when it can replace all human jobs and tasks that it has robotics and parts to do.