> With the horizontal scroll bars, the 320 pixels would be usable
Try reading an article while operating a horizontal scrollbar... it's a horrible experience because every line requires you to scroll from left to right, and then back to the left.
Also, your 800px page will still have a horizontal scrollbar on those devices because they're rendered at 2-3x, making the effective pixel-width of an iPhone 300px-400px. They could just zoom out really far and then use a magnifying glass to read it... thanks to the high resolution that would be possible, but it still wouldn't be pleasant.
> I'm trying to learn. Where am I going wrong? What am I not seeing?
Try visiting your site on a smartphone, a TV, a tablet, etc... you'll see the issue.
Also, your 800px page will still have a horizontal scrollbar on those devices because they're rendered at 2-3x, making the effective pixel-width of an iPhone 300px-400px. They could just zoom out really far and then use a magnifying glass to read it... thanks to the high resolution that would be possible, but it still wouldn't be pleasant.
> I'm trying to learn. Where am I going wrong? What am I not seeing? Try visiting your site on a smartphone, a TV, a tablet, etc... you'll see the issue.