You have missed the point. It is not that there cannot be multiple points of failure; it is that it takes just one point of failure to bring the entire system

You have missed the point. It is not that there cannot be multiple points of failure; it is that it takes just one point of failure to bring the entire system down. As long as there are dependant and moving parts failure will be inherent in the system; it cannot be "inspected/tested" away. Adding redundancy does not remove failure it merely transforms/postpones it. Failure is the "natural" state; we intuitively understand this through the concept of entropy always increasing (or more colloquially; "everything is going to shit") unless we do something about it i.e. expend energy and do work.