Youtube is full of crashes prevented. Spending a few minutes on Google would show you otherwise. If you're not seeing it it's because you have refused to look. You already made up your opinion.
You can't show (least of all on some fanboy Youtube video) that AutoPilot had prevented a crash, compared to a normal person just driving a car. A Tesla crashing into a firetruck -- that you can show.
What you could show would be crash statistics over a significant population of similar cars, in similar conditions, driving on similar roads. These statistics don't seem to show any safety benefit to Tesla, but believers will believe.