Why might VOO be better than SPY, IVV and VTI?

I made 2 videos the other days comparing the historical returns of these 4 ETFs: IVV, VOO, SPY and VTI. In the first video, I found that a VOO had the best historical returns in a randomly chose investment time span. 

In the second video, I found that VOO was still the best accounting for their return standard deviation, or risk, or fluctuation, when I divided their returns by the return standard deviation.

Why might VOO be better than SPY, IVV and VTI?

Out of curiosity, I went digging for information. Some of the known facts that would not make VOO the best:

1. VTI contains mid-, and small-cap equity, while the others don't.
2. SPY has the highest expense ratio of 0.09%, while the others are 0.03%.

Then I found the possible reason, their turnover rate:

1. SPY: 2%
2. VOO: 2%
3. IVV: 3%
4. VTI: 3.4%

With this and the fact that SPY has the highest expense ratio, VOO might just be the best ETF among : IVV, VOO, SPY and VTI.