40% of global ship traffic is simply moving fossil fuels around! Renewables make much of this traffic obsolete
That means fuel will continue to get more expensive as other markets switch to renewable energy sources. That in turn will reduce the number of ships which will make the fuel harder to find, which will reduce the number of products using that fuel, which will eventually result in total elimination of that market.

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.