The ability of fluorine to stabilize the highest oxidation state due to higher lattice energy can be seen in:

Due to increased lattice energy (for instance, ${\mathrm{COF}}_3$) and higher bond enthalpy in terms of more covalent compounds like ${\mathrm{VF}}_5{\mathrm{CrF}}_6,$fluoride stabilizes higher oxidation states. Multiple connections formed with metals enable oxygen to stabilize higher oxidation states. ∴ Fluorides cannot compete with oxides.