Ships are designed with bending limitations, your desk is designed not to bend under the weight of all your technology, and your bones are not designed to bend. Did you also know that smartphones are not designed to bend, even those with a little bit of flex built into them?
Yesterday, ZDNet's Adrian Kingsley-Hughes wrote about the ridiculous video showing what happens to a heated and scratched Nexus 6P. The guy who posted that first video responded to the criticism by posting another video using a Nexus 6P that was unboxed and then bent to attempt to prove the Nexus 6P has structural issues.
While there may be some weak points in the design of the Nexus 6P as a structural beam, placing your fingers in the center of the phone and applying heavy pressure to the ends is a non-scientific test that doesn't model any type of real world situation. The only scenario I can think of where bending matters is sitting on a phone in a back pocket, but the fixed points and applied force distribution is quite a bit different than what is shown with the two hand focused breaking seen in online videos.
I've owned and used hundreds of phones and PDAs over the past 18 years and never tried bending any of them in this manner. They may have all bent if I had taken them in my hands and applied enough pressure. My wife's HTC One M9 recently showed some initial screen separation and deformation in the metal frame due to being sat upon. You would think that is a strong phone, and it is for its intended usage.
When I use a phone, I pick it up in one hand and tap away on the display with my fingers from the other hand. I put it up to my face for a call and then set it down again. I occasionally drop my phone onto a table or even the ground and hope it survives. I never take two hands and try to bend it so I don't care if it bends in that situation.
Evaluation of bending scenarios is carried out by starting with a free body diagram and applying loads and supports. The most common and simplest structural element subjected to bending moments is the beam. Beams are designed to carry loads at right angles to the length of the beam. Smartphones are not beams and are not designed to carry such loads so let's stop testing them as beams.