Airlines optimize to such an extent that they include only the fuel needed to reach a destination, including a safety margin, so on short-haul flights the tanks are mostly empty at takeoff.

I think electric planes could be made to work fairly well for those short flights because the batteries could be kept small. But for long flights the deadweight is going to be a huge problem!

Applications of liquid fuels which are remote, in high fire-risk environments, don't lend themselves to other safety countermeasures during fueling, and don't lend themselves to electrification are tiny portions of the energy market, but still could be quite noticeable in absolute terms.

But that's not why I answered you. I answered in the way I did because you responded to a question "why do you think combustion fuels are a dead-end?". Even if we take the absolute best path for climate and get lucky on some aspects of battery and electrification economics, we're still going to be burning significant quantities of fuels for the next 100 years. They will be markets in significant decline, but still huge.

Diesel is not very flammable. You can drop a kit match into a puddle of diesel and it’ll extinguish the match.

The big difference is that unlike gasoline, diesel doesn’t really vaporize at standard conditions, and it’s the vapors that are so dangerous - the god old surface area effect, the same reason sawdust is much more dangerous than a solid hunk of wood.

Fossil-based hydrocarbon fuels could be replaced by non-fossil synfuel analogues which are themselves carbon neutral. This is based on proved chemistry, though the economics to date have not permitted anything but experimental and pilot-project scales of operation.

One of the appeals of this route to me, however, is that by introducing equivalent fuels to the extant energy system it would be possible to convert to a green, sustainable energy economy without wholesale replacement of extant fleets, powerplants, and energy infrastructure for refining, transport, storage, and distribution of those fuels. In this sense it's the exact analogue of replacing underlying grid generation and storage infrastructure with EVs.

Again, the slight fly in the soup is that neither economics nor the necessary scale of operations are proven, though the prospect isn't obviously unattainable, as many other proposed solutions are. (Say: biofuels, for which biological capacity simply isn't sufficient.)

Diversifying or other future thinking, is far down the list. (As measured by investment allocations)

Hydrogen or ammonia will likely be cheaper to make than hydrocarbons and might work for many uses, like airplanes and ships, that can't use batteries. Hydrocarbons may be only be used for places where can't upgrade.

Synthesized fuels aren't fossil fuels. If you want name, say hydrocarbon fuel.

That's a fairly minor point relative to the emissions picture, which is most significant. But nonzero.

In re: better batteries, we have to ask, "Better for whom?" Tesla has already spun off another for-profit corporation to make money charging people to dispose of their batteries. More exploitive mineral extraction methods are typically cheaper than doing it right. Etc.