Yes, like @joigus and @swansont I don't follow this. Fluorocarbons don't require any less carbon than hydrocarbons, for a given chain length.  The virtue of carbon, surely,  is its unique propensity for catenation, viz. forming long chains, linked by covalent bonds. Your proposal does nothing to lessen dependence on this so far as I can see. Fluorine forms only a single bond, so can't substitute for carbon in this role. By looking at fluorocarbons all you are doing is substituting F for H.