Why is $SPY outperforming $VOO over the past 5 years?

Shouldn’t $SPY be very slightly below because $VOO has a lower expense ratio? I was comparing and SPY has a gain of 46.60% and $VOO is 45.92%. I know people say to pick VOO for long term but shouldn’t you pick SPY if it indeed has higher returns? Is there some other factor that I’m missing out on and these two are actually equivalent but VOO has a lower expense ratio?