Brakes don't suddenly go from good to bad.
Tell Paul Walker.
In fact, brake lines fail without notable warning all the time, as do other components like masters and boosters. So you're wrong there.
Likewise, if you're lacking oil, it's trivial to detect that. There's a sensor that notices when there isn't enough oil and it works trivially easy. Covered in oil = fine, not covered in oil = warning light on.
Actually, this isn't that easy. For example, one of the UPS drivers let me know that his Mercedes Turbo-Diesel powered delivery van was detecting low oil and shutting off when he needed power the most, going up bumpy hills. Almost killed him one time. The fleet mechanic defeated it for him so that he wouldn't die. So you're wrong again. Even Mercedes who has been making cars since time was time can get this one wrong.
And if a light goes dark, it's either easy to notice yourself (when you don't see jack anymore) or some friendly cop will point it out to you (usually while cashing in some money for that service...).
Look, it's not when a light goes dark, which is not easy for most people to notice. It's when a light comes on. When there's something wrong, a light is lit. If your brake fluid is low, your BRAKE light is on. If your vehicle is producing excessive emissions, your MIL is lit. If your manufacturer bothered to also create a CEL, then if there is also likely engine damage occurring, the CEL will be illuminated. When you disable traction control in cars which permit it, something lights up to tell you it's off, nothing goes off to tell you it's no longer on. So you're wrong again.
It's a bit different with the kind of sensors that you need to let a car drive itself. I think the moment you notice that some important sensor is covered in mud is the same moment that airbag goes poof in your face.
I think the moment you notice that some important sensor is covered in mud will be the same moment that the car tells you that there's a sensor problem, and that you're going to have to do your own driving.
You are wrong about literally everything and your conclusion is laughable.