All of these half measures are pretty concerning to me. I think they let drivers feel more comfortable, despite paying less attention, and I think their failure modes may often be much worse than the (human-driven) crashes they purport to prevent.
Anecdote: I once had a rental car with alane-keeping assistance system that would nudge the wheel slightly. On the interstate, upon cresting a hill, I saw that there was a vehicle stopped in the shoulder, and I was concerned someone might step out into the travel lane. I already knew that there were no vehicles behind me in either lane, so I steered gently into the passing lane to give ample space to anybody who might step into the road.
However, in my haste, I had not used the blinker, so the lane-keeping system intervened. Imagine my surprise when the car decided to nudge me back towards exactly the dangerous situation I had been avoiding!
Luckily, nobody stepped out into the road. But if they had, this lane-keeping system could have killed them.
In comparison, even if the left lane hadn't been clear, the hypothetical accident there would have been a comparatively minor fender bender.