If you count a 50% difference as "performs similarly" I have some dollar bills I'd like to sell you for $1.50 each.
Things that are stronger generally tend to last better under use by humans or non-humans, but whether you can bend it with your hands is not a good benchmark. But if it bends in your pocket when you're not intentionally stressing it for the benefit of your YouTube audience, that's more troubling.
The average human male can't even bench press their own weight. 500lb of force is in elite boxing range. You'd basically have to be an Olympic level boxer to be generating that kind of force "fairly easily".
Can a human generate power easily in that range? Maybe if you jumped on your phone from a 2 story building, or had amazing squats and dropped the weights on the phone. But no sane company would design their daily-use general purpose smartphone for those kinds of circumstances.
To give you an idea of what human strength actually looks like here's a paper on hand strength.
http://www.rehab.research.va.gov/jour/70/7/2/swanson.pdf
70lbs is just between the grip strength of a woman and a man.
150lbs is over both.
There are entire categories of human-sized movements that can generate over 70lbs of force. There are surprisingly few that can generate at or over 150. You have to really want to be doing it and you have to be body builder strong.
Stepping on your phone can easily generate twice your body weight in force. While running a heal strike can easily be three times your body weight. Hopping on one foot can go beyond that. http://thebodymechanic.ca/wp-content/uploads/2012/09/giandol... http://www.barefootrunning.fas.harvard.edu/4BiomechanicsofFo...
You might argue that's not what we are talking about, but a phone in your back pocket could easily be subjected to more than your body weight when sitting (flopping?) down on a wooden chair.
PS: One of the classic cellphone tests is driving a truck over the thing. For courtiers it's not uncommon for someone to drive over your phone and generally rugged phones can easily service that.
Personally, I'll be getting a rigid case that covers the back and sides.
Most cell-phone "rigid" cases are less rigid than the phone's own case, so they only afford protection against scratches and impacts, not bending.
Who puts their phone into their back pocket? Why would you do that? Is it because it doesn't look as good to have it in your front pocket?
Because I sure as hell wouldn't put something that I spent >$200 on, that isn't designed to be sat on, in my back pocket.