Why are modern day phones so prone to breaking easily?

Literally I'm not that heavy handed but I've broken so many phones in past few years and high end devices that claim to be the best and have good IP rating. All of them were Sony and one Samsung phone. I always buy phones that have a good rating and is rugged.

So I have a Sony Z5 premium that keep on breaking or stops working. I've had this problem for a while probably since I bought the phone. It overheats alot too.
Here's another thing before you say it's all my fault. Every time I send it off to the manufacturer. I always get a brand new phone no questions asked, leading me to believe that phone model is completely faulty. It's happened multiple times where they haven't bothered or can't repair it but give me a brand new phone instead..

I've had enough of Sony phones. I think all smart phones regards of price point are manufactured to break.