There is no debate because the answer is simple.
To the bottom
See picrel?
That's a desktop on a traditional desk.
Where do you draw stuff from? The side? the top?
No, from the bottom aka front.

>but muh screen space muh wasted pixels
Look at a book. A book is usually something like 16:9 too. Where do you find eg annotations? Or page numbers? on the side of each page? No - on the bottom. It's a convention we've had for thousands of years, people got used to it. End of discussion