From what perspective? The individual flight operators maximize their earnings by running as many flights as they can, and charging as much as they can. Individuals who need transportation also maximize their utility from the same thing.
Some flight operators are planning for shortages by canceling flights: https://www.theguardian.com/business/live/2026/apr/16/uk-feb...
Every business is prioritizing stocking up on goods they need already. They need transport to do that.
The cancellations are because of rising prices, that doesn't mean they can get fuel, just that the current price makes the destination unprofitable. (Technically this should free up some fuel).
But I was thinking from a political perspective, allowing airlines to just fly destinations that frankly aren't needed, like vacation hotspots, seems ill advised, if you truly expect to run out off fuel. The reality is that Europe won't run out of jet fuel, it's airlines can pay for the fuel it needs, for the destinations it requires, but prices will go up. Poorer countries will run out, because the fuel is worth more in Europe and will be redirected.