My 8 yo M3 has radar and it still is active since the yellow radar symbols light up when passing by obstacles. It's also used to figure out obstacles in the front and back and if disabled, the relatively poor cameras on my car would not be able to figure out the distance to the next car in the front.
My shitty Kia Niro has a UI element that indicates anytime it detects an obstacle in my blind spot. My side mirrors even have a red light that also tells me it detects something. Tesla doesn't do that?!
