This isn't entirely true. The cost of gas has a hard floor due to the cost of extracting oil from the ground. Nobody is spending $40 a barrel to extract oil that's selling for $25 a barrel. So if oil demand falls and prices fall, many of the current sellers pull out of the market entirely.
On top of that, as the number of cars going to gas stations starts to drop, gas stations will get less profitable. As profits drop, stations start closing down. Eventually, enough stations close down and it becomes inconvenient to own and operate an ICE vehicle regardless of the cost of fuel.
