Why are there buttons on the bottom of a cell phone where your palm would activate everything via heat if you pick it up from the front?

On my old iphone 6plus and my new galaxy. Everytime I wake up and grab the phone to shut down the alarm. Since I'm grabbing the phone pretty unconsciously. By the glass part.

I'm usually warm so my palm, if it goes near the buttons. The heat activates ALL the buttons at once.

Then the alarm stays on while every app on my phone starts to open just because I'm near those buttons.

Why can't the buttons be on the top near the ear part? This is just how I grab phones because the designs are so stupid and slippery.

Buttons at the bottom seems like some sadistic torture idea for people with normal sized body parts. If I was a child or someone from a culture who builds these my fingers would obviously only be an inch long so it wouldn't be an issue. But I'm 6'.

Not everything has a reason

I'll bet that would be alleviated by enabling the PIN for the lock screen. That'll keep the home screen away from your sleepy fingers until you did something intentional.