Work effectively, but be unpredictable. You are irreplaceable when you contribute in a way that AIs struggle to model or imitate.
Aim to be effective, but unpredictable. That is, you want to act in a way that AIs have trouble modeling or imitating. That makes you irreplaceable. Working differently is usually more productive than working harder.
I also like how Kevin Kelly put it in the context of storytelling: "To tell a good story, you must reveal a surprise;. otherwise it is just a report." AI is very good at writing a report.