Just to nitpick: Tesla is, in fact, not at all far ahead of other auto manufacturers in terms of autonomous driving tech. At CES this year, pretty much everyone showed off significant achievements in their own self-driving cars, including fully autonomous road trips. Autopilot is basically the same as adaptive cruise control + traffic jam assist, both of which have been available in some vehicles (Audi comes to mind) for years.
The difference is that the bigger OEMs are extremely wary of enabling these features in cars and getting into lawsuits as a result. Tesla has shown repeatedly with things like a giant touch screen that flaunts NHTSA guidelines that it just doesn't care about potential legal problems, and is more than happy to put somewhat unproven tech in the hands of drivers and hope for the best.