Somehow Waymo built their system without having their test cars drive into buildings, nudge other cars off the road, honk incessantly, drive backwards just for the heck of it, etc.

I can't say whether you are being sarcastic, but Waymo has its share of problems. For example, see NHTSA recalls 24E013, 24E049, 25E034, 25E084, 26E026, 26E035.