So you're correct to call it a tool, with this level of automation the driver is ultimately the operator. But you're missing something

Did you misuse the tool, did they sell you a bad tool, or did their instructions cause the tool to be misused?

The first is as you said - if I make and sell you a circular saw and you cut your finger off being an idiot, that's on you.

If the thing flew apart under normal use, that's on me - it's likely my responsibility, and possibly negligence.

If the box or user manual said it is for wood and metal use, and it's actually entirely unsafe for metal use, that's probably negligence on my part

Cruise control doesn't unexpectedly jerk your wheel to the side, if it did and you could prove you were using it reasonably and in the recommended way, you'd almost definitely get off the hook