The side mirror blindspot sensor warns you when a car is in your blindspot. It makes the decision FOR you (safe, or not safe to turn). If it fails, you have no way to know this. The “failed to detect” case is equivalent to the “it’s safe to turn” case! This is the “solve” way.
By contrast, the rear view camera solves the same problem but via the “surface” way: it does NOT tell you whether it is safe or not to turn. It just shows you what’s there. You decide. If it fails, you can tell that it fails (the camera stopped working).
- Fact checking systems are “solve”, community notes is “surface”. It doesn’t tell you what is truth, it lets you decide.