Requiring that you sit further back is built on the notion that you need to be able to see your entire workspace at once, which was never true with an actual desk and largely implies that you want a single document to take up the whole screen. If you remove that limitation, then you find yourself with a larger workspace with elements at a comfortable size to work with.

I do prefer to turn my head side to side rather than up and down, so right now I'm happiest with a 5120x1440 49" monitor and may consider a 7680x2160 57" monitor sometime in the future.