On the other hand, if you average the Sun’s energy generation across its entire volume and adjust for that volume’s mass, an equivalent mass of human body tissue generates more heat energy.
So your eyes may not have the raw lumen output of an entire star; but, pound for pound, your eyes would outshine a similarly massive piece of one.
Yes. On average.
If you specifically take 100 kilos of core material from the Sun, then it would be a no contest victory for the Sun. But the Sun is very, very big, and when it comes to producing energy, most of it is doing absolutely nothing. So it brings the average energy production per kilo way, way down.