In this answer, when I mention oxidizing ability of an acid, it’s implied that it’s of the acid’s conjugate base, for example, SO−4SO4− for sulfuric acid, because all Brønsted acid can donate H+H+ ion, which can oxidize.
I would not say sulfuric is a strong oxidizing acid. It only shows oxidizing ability when it’s concentrated, whereas other acids like nitric acid or chromic acid can oxidize when they’re dilute. Their conjugate bases can even oxidize in basic solution. In addition, the oxidizing ability of sulfuric acid is only only significant when it’s heated.
However, it’s strong enough to oxidize some substances that H+H+ ions can’t, such as CuCu or Fe2+Fe2+.
It can because… it is. In acidic solution, the electrical potential is high enough, SO2SO2 is stable enough, so it can.