That's why I use horizontal screens as well.

If you're looking at a screen or paper all day, you want narrow text to avoid a lot of unnecessary eye movement, and relatively short windows so you avoid unnecessary head movement.

Readability is still a good reason for keeping functions narrower than 80 columns and shorter than 24 lines.

Moving the monitor a bit further away from you and/or tilting it (which looks a bit unnatural, having your monitor "facing up" slightly) solves that problem for me.

I've only used 22" monitors vertically, maybe bigger ones are just too big for vertical use and worsen the issue you've experienced.