I hit it accidentally all the time. Any time I have to temporarily one-hand it with my right hand. The sides are rounded and smooth and there are buttons on the back and top of the side. The power button is very sensitive as well and doesn't require a hard press; it responds instantly.
Are we talking about the right button?
https://cdn.shopify.com/s/files/1/0253/3664/3635/files/641_e...
You would have to go out of your way to grip it in a way you could press it. You don't need to move your hand to lift it, it's controller shape after all. Or you can grip it along the bottom edge. And even gripping the top edge I just can't find a way you could accidentally hit it. It's flush.
The only time I've accidentally turned it on/off is when I've been clawing it out of the carrying case.
Edit: Wait, are you gripping the bottom and top edge at the same time, over the screen? Why? It's huge.