Pelton highlights that there is a safety key required to operate the machine and that parents are instructed to store it in a secure location inaccessible to children. [1] No treadmill manufacturer can ever fully eliminate the dangers of an active treadmill to young children and pets, and therefore I think this safety key is the essential piece. I find this similar to locking power tools away from curious young hands.
I don't want this to lead to additional regulation and compliance. Such regulation could even mislead consumers as to the danger of a treadmill. E.g., requiring some autodetection of a stuck belt to stop the motor. A foolproof mechanism would be not only expensive, but require regular inspection and maintenance to guarantee it performs this function. One could trust this mechanism while neglecting maintenance and therefore be further negligent in not securing the safety key away from children.
[0] https://www.youtube.com/watch?v=onXNnlCYJ4Y
[1] https://www.consumerreports.org/product-safety/peloton-plus-...