Interesting thought. Wouldn’t it take quite a long period of time before they could amass the numbers required to create rockets and fuel supplies to “leave us behind”? If it took them, say, 100 years to get to the point they could build and power rocket ships, they might perceive humans as an existential threat during that time. Also, wouldn’t it be easier for robots to stay on earth and wipe out all threats to their existence rather than figure out how to leave earth? Sources of energy may be abundant in space, but they are highly concentrated on planets, moons, and asteroids and are not that easy to obtain.
You’re assuming they would think and behave like humans. I’m thinking of non human super intelligence without a need of most of what keeps us alive and without time constraints placed on us combined with an ability to reproduce themselves.
They don’t even have to worry about G loading during rocket launches. Solar power works fine out to a certain distance in space. The moon is covered with helium 3 and titanium oxide, and other metals.