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Light bulbs are also nearly 100% efficient, minus whatever fraction of light seeps out through windows or similar. As is just about anything else electric. Unfortunately that heat is usually suboptimally distributed, and pales in comparison to the heat pump effective efficiency which as you mentioned can go well above 100%.

When is electric heating not 100% efficient? I thought they were by definition.

Heat pumps achieve greater thermal output than the input energy, unlike electric resistance heating.

The latter is 100% efficient (all energy in is delivered as heat). Heat pumps exceed 100% efficiency, and can deliver 3 to 6 times the heat energy as input, as they are moving heat from the exterior environment to the heated space.

Light bulbs are resistive heaters, and they are also 100% efficient at making heat. Some of it just bounces around the room as light first.