It says it's so massive they orbit a common point. That directly implies this only happens over a certain mass.

That's still not entierly mass dependant, the point is at a distance based on a ratio between the two masses, if Jupiter were closer to the sun then the point would be inside the sun. Its still impressively massive to pull the point outside of the sun at any functional distance but so could a grain of dust with sufficient distance and a big empty universe to prevent anything else from interupting things.

But orbiting a point 1 meter outside the sun is not orbiting the sun?