The Chinese manufacturers and the American companies who utilized them were focused on their profits, not your pets. If a human becomes sick or dies because of a defective product, the company can be sued for millions. But if a pet gets sick and dies as a result of consuming the said product, it will only get sued for however much the pet owner paid for its pet.
The human bone is stronger than steel.
If you were to have a bone and a piece of steel of the same length and thickness, a bone would be five times stronger than the steel bar. However, bones are brittle and can also fracture on impact.