Yes indeed. If one wanted to show the most on a screen, then the optimum ratio would be 1:1. Of course, it wouldn't be very comfortable to use due to human anatomy (ie eyes side by side) especially at large display sizes. I've seen specialized monitors that use a 1:1 ratio, I think for medical imaging.
Personally, I find 16:9 is better for gaming, while 16:10 is better for productivity. I prefer 16:10 for productivity now compared to the old 4:3 ratio of the CRT monitor, finding it more comfortable.