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There isn't a single rocket fuel.

Some launch systems fly on hypergols (hydrazine is one of them; it is not used in the West anymore as a main fuel, being too toxic), some burn hydrogen with oxygen, some burn kerosene (RP-1), a new system is coming online that actually uses methane (Starship).

And these were just the liquid propellants. There are also solid fuel rockets.

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Are you implying that any of those isn't or couldn't be produced synthetically or as a biofuel?

Hydrolox could certainly use all electric production but all of the others require hydrocarbons as their feedstock. Take hydrazine, it's synthesized by oxidizing ammonia and the main feedstock for ammonia production is natural gas and it's synthesis produces CO2 as a byproduct. So we're right back where we started. Why don't we just use hydrogen and oxygen? It's true that storage is a problem since hydrogen must be kept at cryogenic temperatures to remain liquid but a bigger problem is hydrogen's low density. Low density means more volume and that leads to inefficiencies in the size of the rocket. Methane is generally the better option and coincidentally could use captured CO2 as a feedstock.

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