The rental cars I have driven with lane keeper functions have all been too aggressive / easily fooled by visual anomalies on the road for me to feel like I’m getting any help. My wife comments on how jerky the car is driving when we have those systems. I don’t feel like it’s dangerous, and if I were falling asleep or something it could be helpful, but in 40+ years of driving I’ve had “falling asleep at the wheel” problems maybe 3 times - not something I need constant help for.