Not if it's a matter of a persons typical usage patterns exceeding some sort of structural limit. If 0.02% of people typically put too much pressure on the phone in their pocket, and 99.98% of people do not, then the 0.02% will have any iPhone 6 rapidly fail, and the 99.98% will see failures only after an unusual incident or after receiving a weaker than normal phone, and thus at a much slower rate.