An example: A friend worked on accurate built-in weighing machines for trucks, which could measure axle weight and load balance to meet compliance for bridges and other purposes. He found it almost impossible to make units which could withstand the torrents of chemical and biological wet materials which regularly leak into a truck. You would think "potting" electronics understands this problem but even that turns out to have severe limits. It's just hard to find materials which function well subjected to a range of chemicals. Stuff which is flexible is especially prone to risks here: the way you make things flex is to use softeners, which in turn make the material for other reasons have other properties like porosity, or being subject to attack by some combinations of acid and alkalai.

These units had NO MOVING PARTS because they were force tranducers. They still routinely failed in service.

Rubbish includes bleaches, acids, complex organics, grease, petrochemicals, waxes, catalyst materials, electricity, reactive surfaces, abrasives, sharp edges..

They are not saying "dont try" they are saying "don't be surprised if it doesn't work at scale, over time"

Humans can generally stand this without an issue.

In fact you wouldn’t replace a lot of jobs that involves this : doctors, nurses, emergency workers, caregivers…

It just happens to be difficult. But people love doing difficult things as long as it’s : a) rewarding, b) respected, and c) sufficiently paid