Do not underestimate the impact of transitioning from incandescent to LED lighting. An average home could be consuming 1Kw for lighting alone at busy times.
Where heating is needed, and where heating is done by electricity, changing to LED lighting indoors don't make any difference whatsoever. Unless your main heating source is a heat pump. In my home there's a heat pump upstairs, but not downstairs. All the lights downstairs are now LED, but the only effect that has is monetary - LED lights are way more expensive, and contrary to claims, don't last longer either. But these days LED is the only option available when buying.
Heat pumps though.. they really save a lot of electricity. Very visible on my electricity bill.
Is this really a lot of people that use resistive heating?
Also at least it saves electricity during summer when you don't want to dump even more heat into the room.
As a side, from my experience LEDs last significantly longer than incadescant LEDs. Maybe it's something to do with the power grid fluctuating more in certain areas?
I haven't been able to find reliable LED lighting, except when compared to particularly low-quality incadecent lights. Cost-wise it's a no-brainer, LEDs are more expensive. They are, however, getting better. They used to be totally terrible, at least that's changing. However, they're still advertising "N hours", where the "N" counts only 3 or 4 hours (typically) per day, so (and get this) the calculation is something like this: "20000 hours = 833 days, if you use them 3 hours only, of those days". Whereas the incadecent light bulbs "1200 hours" is 1200 hours of actual use.
As for your question, living in a country where 100% of domestic power is electric (save the occasional wood heater which is more for decoration but can be useful in certain very cold areas during winter), yes there's indeed a ton of resistive heating. All the heating in my home is resistive, except for the heat pump in the living room. And the living room is upstairs. The house is very well insulated though, even for a house many decades old, so it's not that expensive to heat.
In the summer? Well, this far north it doesn't get that hot, and we don't actually need to use electric lighting at all during the better part of summer, unless the room is windowless. 24 hour daylight.
Just transitioning from coal to gas for electricity production has a big impact.
The graph is adjusted to compensate for the efficiency of the power plants, but it's an average and one they need to update every so often as plants get more efficient.
But we're phasing out the oldest and least efficient coal plants and replacing them with gas plants that are twice as efficient (33% vs 64%).
The graph under discussion assumes 40% as discussed here: