
The big costs comes from building the infrastructure for fossil fuels. So as soon as demand falls, you have a huge part of the bill has been paid already. So you get low fossil fuel prices. You need to keep in mind that most large oil producers are state owned. Therefore those states will try to shut down other suppliers production.
You can see that already with sanctions against Russia and Iran to keep US oil producers going strong.












Diesel is used for trucking, which can be electrified and for heating, which also can. Bunker oil is mostly used because it is cheap. Jet fuel also can be replaced using high speed trains for quite a few journeys and for short ones there are electric planes. Industrial gas use is in many cases just heating, which can be done with electricity as well.