Edit: was curious, so I did the math. The standard unit seems to be 'crashes per 100 million miles' so according to the Tesla safety report (only source on Autopilot safety I could find easily) that works out to [0]: one accident for every 4.41 million miles driven = 22.7 accidents per 100 million miles.
Without autopilot, the AAA foundation (again, easily available source, feel free to find a better one, this is from 2014) [1] says that our best drivers are in the 60-69 age range, and have 241 accidents per 100 million miles. Our worst drivers are our younger teens (duh) with 1432 crashes per 100 million miles.
So unless you can find better data that contradicts this, Autopilot seems like a net benefit.
[0] https://insideevs.com/news/537818/tesla-autopilot-safety-rep...
[1] https://aaafoundation.org/rates-motor-vehicle-crashes-injuri...