Tell that to some Nexus 5X owners, who experienced boot loops because (the leading theory says) the CPU contacts to the board were becoming broken by excessive

Tell that to some Nexus 5X owners, who experienced boot loops because (the leading theory says) the CPU contacts to the board were becoming broken by excessive heat while applying a system update. Mechanical failures do happen with solid state devices, even if they are operating within their specifications. Manufacturing defects (and gaps in testing), inadequate validation of all conditions within the spec, and/or inaccurate predictions of failure rates over time can all cause this.