Those failure rates are nonsense based on theoretical limits. In practice: a few weeks ago I resilvered a 4 disk z1 array with 8tb disks at 85% capacity in less than 24 hours. I scrub the pool every month and it didn’t seem any more taxing than a scrub.
Found this from yesterday: https://phys.org/news/2024-10-fast-quantum-entanglement-scientists-attosecond.html