7.3 Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?

Gibbs free energy of formation$(\Delta _{f}G^{0})$ of  $Cu_{2}S$ is less than that of  $H_{2}S$ and  $CS_{2}$ so that hydrogen and carbon are unable to reduce
$Cu_{2}S$ $\rightarrow Cu$. But the Gibbs free energy of formation$(\Delta _{f}G^{0})$ of $Cu_{2}O$ is higher than that of CO. So, that carbon can able to reduce
$Cu_{2}O$$\rightarrow Cu$.  Therefore the extraction of copper from its pyrite ore is more difficult than its oxide ore through reduction.