Why is the highest oxidation state of manganese in fluorides +4 (as in MnF4​), while the highest oxidation state in oxides is +7 (as in Mn2O7​)?

1. Fluorine is more electronegative than oxygen
2. Fluorine does not possess d orbitals
3. Fluorine stabilises a lower oxidation state
4. In covalent compounds, fluorine can form a single bond only, while oxygen forms a double bond