It's basically too hard to automate, yes. These may be mundane sounding tasks like checking if a screw is properly secure, we're still far from full automation, the robots simply do preprogrammed tasks, they have no sentience or intelligence.
Checking things like bolt tightness is a hybrid automation. There are machines which know where all the bolts are within a given area, and can test each one and adjust as necessary to make sure they are torqued. But that machine is itself handled by a human that gets it to the right spot.
