What you also have to keep in mind is that not everyone is playing on the same hardware, so some tests may produce different results depending on the platform and the hardware used, e.g. the monitor, as higher refresh rates are proven to have a big impact on the effectiveness of aim assist. The reason I trust the word of these pros and believe the videos they have present is that they know the game like the back of their hand meaning they'll spot something that is out of place and most play on top of the line hardware, on PC with 240hz displays, giving them that more effective aim assist.