the biggest fallacy of efficiency

Most ways to save electricity at home do not save electricity at home.

Those old incandescent bulbs used their electricity 100% efficiently. They used a small portion of the energy to produce visible light and the vast majority of the energy to produce heat. If you heat your home, some portion of the heat comes from your heaters and some comes from your lights (and your electronics, refrigerator, oven, and so on). If you reduce the heating contribution from the lights (and everything else) by investing in expensive high efficiency devices, your heater will have to work harder to pick up the slack, effectively eliminating any possible gains.

If you live in an area where you use A/C most of the year, though, the opposite is true. Any reduction in energy use in the house will be matched by a similar reduction in cooling load, so efficiency improvements will be matched by more efficiency gains.