The first Model X has Autopilot 1 which was a system designed by Mobileye. Tesla’s relationship with Mobileye fell apart and they replaced it with an Nvidia based system in 2017(?). It was really really bad at the start as they were essentially starting from scratch. This system also used 8 cameras instead of the original 1.

Then Tesla released AP hardware 3 which was a custom-built silicon chip designed specifically for self-driving which also enabled proper navigation of surface streets in addition to the just highway lanekeeping offered in AP1. This broadened scope of actually dealing with turns and traffic from multiple angles is probably where the reputation of it being dangerous has come from.

My HW3 enabled Model 3 does make mistakes, though it’s rarely anything like hitting a pedestrian or running off the road. Most of my issues are with navigational errors. If the GPS gets messed up in the tunnel, it’ll suddenly decide to take an exit that it isn’t supposed to, or it’ll get in the left lane to pass someone 1/4 mile from a right-exit.