Doesn’t the term “fuel” imply they are burnt? Genuine question, I’m not native speaker

Fuel is simply a noun for a source of energy, it doesn't need burning for something to be fuel. Look at nuclear fuel - it doesn't burn.

Yea. That last part is a bit incongruent. My bad.

Modern medicine relies heavily on petrochemical feedstocks (derived from fossil fuels.) These are used to make plastics, solvents, reagents, packaging, and some pharmaceuticals Many of these materials currently have no scalable, cost-effective substitutes.