If you reach for the top left corner your thumb will naturally come into contact with the bottom right corner of the screen, assuming you are holding the device one-handed (in your right hand).
I’m trying to picture this, but I can’t. If I hold and lock my iPhone with my right hand, I press the lock button with my thumb. If I try to reach the top left corner, I either do that with my left thumb (mostly) or index finger (sometimes), or with my right thumb (very awkward movement on a Pro Max). In none of these cases my right thumb comes in contact with the screen or even close to it. Maybe because I use the backside of my pinky finger to lock the phone in place.
