Because we haven't gone back to normal, we're effectively running on back up supply, using what used to be secondary sources..
This is one for the oil industry experts but as I understand it we only got where we are now by in effect shifting to alternative sources, in the case of Europe perhaps looking to the US to plug the gaps due to lack of output from the ME, but sometimes at a cost.
If the supply chain gets further throttled there may well be no third tier of supply to further fall back on.
And then fuel prices came down again and everyone had a lovely holiday.
Actually in the aviation world they didn't really come back down that much and not for long...see the IATA website I linked to in a post upthread.
Most (but not all) companies got by without widespread cancellations because those supplies from secondary sources arrived, and because many companies had hedged their fuel contracts into the autumn.
Even if supply continues IMO if the jet fuel price stays where it is now some people will not be going on the holidays they have booked for next year and/or fares are going to escalate fairly quickly.
Now I know "if" is doing a lot of heavy lifting in there but the airline situation is looking slightly scary from the POV of someone who used to work in it and has seen the ups and downs of several economic cycles.
If you want my advice with regard to flying this winter and beyond - assume nothing, book with a credit card, make sure travel insurance is comprehensive, and don't start grumbling it is just the airlines are gouging if fares and other fees start going up..