I beg to differ. That light becomes heat when it's done being used. Numerous tests show it to be true.
The point is that an efficient source produces the same lumens with less heat. If, instead, you take more lumens with equal watts, you get equal heat - with more lumens - but still equal heat.
Believe me, I looked into it thoroughly, because it seems wrong. But it isn't. Watts are heat = same, same. The light becomes heat, but first we get to use it, so we get more light, yes. But equal heat with equal watts.