Sure, there are various inadequacies in the data, Tesla is clearly not an unbiased source (though there has been some verification from gov agencies), but I think the rapidly decreasing accident rate is significant (even when compared to the same car without those features), and we'll see numbers continue to improve over time.

Most people are simply not careful drivers all the time. This is one major advantage computers have - they don't get tired or distracted.

Time will tell as we get more data about supervised driving, but I think it's inaccurate to say we don't have data yet, it is imperfect of course, but it does point to computers being safer than humans in some very common conditions over millions of miles.