I found out the genesis of this entire issue yesterday while watching videos by Tesla’s head of AI and Autopilot,
Andrej Karpathy - apparently, Elon challenged his team to use AI and video stream inputs instead of traditional rain sensors for controlling the wipers. He poked fun at the entire thing, even showing a video of someone pouring ketchup and corn flakes on the windshield to simulate rain. In the end, he concluded that it finally works pretty well. I think most of us still disagree. An improvement- yes, but still behind expectations and performance of traditional cars.