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.
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.
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.
Under those kind of extreme conditions, I'd have no choice but to go with the most rugged possible phone. I think I have an old Nokia around somewhere.
