16:10 would equate to 8:5... that would be a wacky screen size haha
My desktop monitor is 16:10. It doesn't seem to be "wacky"... (1920x1200)
The only reason 16:9 is seen to be 'normal' is because it's the de facto video proportions for WS TV and therefore a video 'standard' aspect ratio as was 4:3 in its day. I suspect that it's use in phones is a convenience rather than a must.