If your primary use of a computer is for gaming or video playback, then 16:9 does seem the right choice. If that is your use case, having anything taller than 16:9 means all of those extra pixels will primarily only ever be displaying black. What's the point of that? If your primary use of a computer is anything but games/videos, then the occasional letterboxing is much less egregious. As a gamer, instead of paying for more pixels, that money can be spent on faster refresh. Less pixels also helps allow for faster refresh, etc.

At home with TVs, I'm okay with the letter boxing to watch 1.85,2.35 type content on my 1.78 screen. It's the trade off as making a movie buff 2.35 screen would force majority of 1.78 content to be window/pillar boxed.