I own latest 5 series bmw and paid for all the driving assistance add-ons, and while the adaptive cruise control is awesome, the line keeping assist is complete

I own latest 5 series bmw and paid for all the driving assistance add-ons, and while the adaptive cruise control is awesome, the line keeping assist is completely useless and works absolutely terrible, not sure who decided to charge money for this incomplete piece of software, it's unusable, my friend has a model X and it's a day and night difference between the two, Tesla autopilot is just in a different league compared to bmw line assist thing.