I spent WAAAAAY too much time making this.
@cuchaz Target Audience.
I rarely need to use my phone as a "phone", instead wanting a pocket computer with plentiful visual realestate for reading/watching/scrolling and usually I am able to use it two handed at my desk or other things.
If i really need to use it one handed Samsung has a "one hand" mode that shrinks the screen down to a thumb reachable size just by touble tapping the home button. Looks like this.
@ticktok whaatttt??? That's amazing! 
@cuchaz yup, you can change what side it's on as well as scale it to your prefered "zoom" and it will remember it.
https://www.samsung.com/au/support/mobile-devices/using-one-handed-mode/
Using One Handed Mode on my Samsung Phone

FAQ for Samsung Mobile Device. Find more about 'Using One Handed Mode on my Samsung Phone' with Samsung Support.

Samsung au
@cuchaz @ticktok my Android phone (Pixel 5a) also has this, I just swipe down from the bottom of the screen. I think Apple has something similar.
https://support.google.com/accessibility/android/answer/12652418?hl=en
Use one-handed mode - Android Accessibility Help

Important: Some of these steps work only on Android 12 and up. Learn how to check your Android version.

@jasoncoon @cuchaz
neat. the samsung version keeps the screen aspect ratio so you can still type and interact with it as if it's just a smaller phone. I just uploaded a video here
https://fosstodon.org/@ticktok/109701659058523680
Ticktok (@[email protected])

Attached: 1 image @[email protected] idk. I have average leaning towards small hands for a guy and this is how I use my samsung Note20 with a 6.9" display, and I have a wallet case on it. but like I said, I'm the target audience for phablets though.

Fosstodon

@ticktok @cuchaz ios has a similar thing where swiping down on the bottom edge slides the whole screen down, so that you can reach the buttons in the top half (the bottom is then hidden). it's only made for like one tap on or to open the notifications drawer, so it goes back to normal after that one tap/swipe. still useful though.

another thing they have is you can make the keyboard narrower, leaving some blank space on one of the sides (you choose which).