I’m not saying this is OP, but some people are just rough with their stuff and don’t realize it. For example, someone I know burned the on-screen keyboard onto their screen because they disabled the screen dimming function. That’s not something I considered possible. Other people drop or throw their phones onto desks or lay them face down and scrape them against the surface when picking them up etc.

It all seems fine until eventually one day the phone stops turning on.