I still like the heat pump because in the summer my power bill for cooling a 2600 sq ft home is about $50/month, and in the winter I do have a wood burning stove that I can run to heat the house when the temps are below 36. That and recirc mode on the fan unit can keep my power bills to a minimum.
Year round? So you mean the polar regions? Because they can work even at -10F. Efficiency is reduced, but they can work. Crappy ones will cutoff earlier though. If you are not in one of the planet's poles, we have seasons so it's better to use LEDs for at least 3/4 of the time (maybe more as even northern latitudes only have a few really severe winter days).
Modern LED lamps are tiny and use very little material. Incandescent bulbs are no longer considered 'exotic' because of how old the tech is, but tungsten was a very exotic material at some point.
That's the point where I'd strongly consider cryptocurrency mining.
Switch to LED and your heating system will need to supply that extra 0.5kW.
In a climate where you are almost always running heating, this makes the benefit of switching to LED much smaller, and considering that they are much less environmentally friendly to produce, it may even tip the scale the other way.
Depending on where the bulbs are located, they may be emitting into a ceiling cavity that exits the building's envelope more quickly than the location of the heating coil. Some bulbs are actually outside the building.
And of course, the heating system can supply 0.5kW for less than 0.5kW of power with heat pumps or (net including generation and transmission) natural gas.
Beyond that, heat pumps are still much more efficient than direct electric heating.
Also, if you have air conditioning at any point in the year, those incandescent lights are just going to make your air conditioner work that much harder.
How would that be the case?