I have driven a car with lane keep assist and hated it. If I'm getting close to the edge of a lane, it's intentional and often for safety; having the car try to interfere with that is counter-productive. I wouldn't call it comparable to Tesla's autopilot though, as it only intervened in steering when you neared the edge of the lane. I guess you could just let it pinball down the road like that, but I wouldn't want to attempt it. Maybe other cars do it better.
Adaptive cruise on the other hand is great, but all modern cars have that.
The real issue though is that it's harder to remain alert when the car is effectively doing everything for you... until it doesn't.