Well, my work place has gotten many of the M1 units back from customers, and I and others test them and the program we use, along with DriveDX, says they are failed, or very worn, below 50% life left....and they are only 2 months old.
A ssd's life is can old be as good if it is made well...we have used ssds that don't last 3 months, like recently, Mushkin 2.5in ssds 500gb and 1tb, most have failed repeatedly and we have gotten returns/repairs request. And, we work with, and get them from the manufacture direct. They investigated and stated, they found Apple computers are far more picky on ssd quality as they stuck the same "failed" ssds into pcs and they worked with Windows fine, but a macbook or Apple computer would not even install the os on it, and error out. They then sent us a batch of ones that they claim have "tighter manufacture tolerances" and so far, appear to work and not fail.