It all reminds me of the gas crunch in the 70’s where people were making their own “diesel” out of used fry oil just to have a local supply and to save some money.
Fast forward to today and SAF is more expensive but the normal fuels are more available and cheaper!
This is all pure lunacy that is based on a fallacy and being sold as enlightenment.
“There is always a well-known solution to every human problem – neat, plausible, and wrong.” H.L.Mencken