A better presentation of this data would show a failure rate for each brand and month/year of purchase. For extremely simple devices like resistors or incandes

A better presentation of this data would show a failure rate for each brand and month/year of purchase. For extremely simple devices like resistors or incandescent light bulbs, failure rate is relatively constant over the lifetime of device -- the chance of a functioning resistor with 10 hours of use failing during the next hour is the same as the chance of a functioning resistor with 1000 hours of use. For complex devices with lots of interdependent parts, some of which are mechanical, the failure rate changes over time. There's an "infant mortality" or "lemon" phenomenon, where relatively new devices have higher defect rates (because fabrication and shipping sometimes result in imperfections which quickly cause failures), followed by a steep dropoff in failure rates (because observing a device operate correctly for dozens of hours is strong evidence that it doesn't suffer from a failure mode which often results in infant mortality). Then there may be an increase in failure rates later, especially with devices that are partially or wholly mechanical (wear or damage type problems which do not cause immediate failure, but make it easier for a failure to occur). You need empirical data to be quantitative about this curve, and it sounds like Backblaze has it, but their presentation in this article doesn't show it.