Cooler bulbs seem to generate a larger fraction of their energy in the infrared. Hotter bulbs generate not only more light, but a greater fraction of that light is visible.
This is easier to think about, if you consider the extremes. A very low power bulb generates no visible light, but still consumes energy. This is super inefficient. At higher temperature the peak shifts to longer wavelengths (i.e. visible). You can compare the black body radiation at different temperatures using Planck's law.[1]
[1] https://en.wikipedia.org/wiki/Planck%27s_law#/media/File:Bla...