Which places you, the reader, fully in control of the width of lines you prefer to see. Adjust your browser window width, or apply a user style sheet to tell your browser to format the text the way you want to see it formatted.

I see. I don't have a wide-screen monitor (still using an old tube type until it finally expires but it's taking a few decades, lol). I've wondered whether people actually like reading websites on wide-screen. Some do and some don't. What would you suggest for a max width?

You could also try zooming in. My apps don't expand to full width because of the video box but you can zoom.

I have the opposite problem. I typically have many browser windows open at the same time but only two screens, and many sites that I use are designed to assume that everyone has full-screen browsers.