What does one expect when you subject a deliberately thin electronic device to the full force of your body?
It's not unusual for a fair amount of strain to be applied there.
For you and other people, apparently not.
My Samsungs, HTC's, and older iPhones did just fine with me exercising exactly no intelligence when I put them in my pocket.
• I then make sure to buy pants with front pockets deep enough that my phone is not being pressed into my groin when I sit;
• and I take my phone out of my pocket if someone is about to sit on [or straddle] my lap, charge into me at waist height, or drop a large object on my leg while I'm laying on my side.
You know, common sense.
I mean, I do approach the problem from the other direction as well; one reason I don't buy a phone that's approaching phablet size (other than not being able to hold the things in one hand) is that it wouldn't fit in the pockets of most pants, greatly narrowing the range of pants I could wear (or necessitating an—admittedly probably cheap—tailoring to add deeper pockets.)
But as it stands, I'm not limiting myself much—my phone is only slightly larger than my wallet, so I'm just avoiding clothes that not only wouldn't fit a phone, but wouldn't fit a wallet. There aren't that many pants (for men, at least) that have pockets that small/shallow/tight.