CFC is a fluorinated gas. Its in the name. Chloroflurocarbon. So you're saying "Fluorinated gases replaced [fluorinated gasses]".

CO2 is not a terrific refrigerant. It requires comparably very high pressures to be effective and has a low critical point reducing their effectiveness in a lot of normal temperature ranges. More modern refrigerants like HFOs usually have a GWP of <1 and don't require anywhere near as high of pressures, with R-454B being around the same as R-410A.