Electricity is usually not made from fuel

You’re generally wrong on that:

“Over 60% of global electricity generated so far in 2023 was produced by fossil fuels” --Reuters

Belgium is what’s relevant in the case at hand. In Belgium ~20% of power is from solar, wind, and hydro. The other 80% is from burning fuel. I group nuclear with fossil fuel because the nuclear power plant in Belgium is being decommissioned and will be replaced with 3 new gas burning plants.

Gas stoves are far inferior in this step, losing most of the heat into the surtounding air. Induction stoves have almost no transmission loss.

That’s true but that’s stoves not ovens. You’d have to exaggerate quite a bit to claim more than half of the heat energy is wasted on gas stoves or ovens.

In order to use gas in the kitchen, you have to have a gas pipe in the kitchen, which has become very unusual.

Where? Unusual Belgium-wide? The cities concentrate populations. Brussels city is mostly old homes likely all piped with gas judging from the dominance of gas boilers. Are you saying there are lots of old homes that did not bother to branch a gas pipe into the kitchen?

During construction, it's easier and cheaper to not lay gas pipes.

That’d be a false economy. Pipes are like ~€7 per meter so it would take ~1—2 years for the pipes to pay for themselves if they are used for daily cooking.

Most people do not have a choice – either you got an old house witha gas pipe in the kitchen or a newer one with a 400 V power outlet.

I do not have a 400V outlet. I have no idea how many electric ovens require that, do you? I’m using a crappy portable 220V oven. If the big properly insulated wall ovens are 400V, then I would have to run a new line to the fuse box. Not sure if I could wire that myself, which I assume involves bridging two 220V circuits.

I guess most people don’t do their own work. So you are implying hiring someone to add one or the other post-construction would be cost prohibitive. Sounds reasonable. But I’m not convinced kitchens lack gas pipes to begin with because gas stovetops are still popular in Belgium. Just not gas ovens.

(edit) In Brussels in 2011, “natural gas consumption was 10,480 GWh and the electricity consumption was 5,087 GWh”, according to Wikipedia.