It used to be that people set the width of their browser window to the text page width they’re comfortable with, and configured a different font if they didn’t like the default one on their browser.

We should be more ambitious in letting the browser software control the presentation according to the user’s preferences. This is not facetious. We should use the increased ease of building software to create software that is flexible, empowers the user, and accommodates different user preferences.

Please don't complain about tangential annoyances—e.g. article or website formats, name collisions, or back-button breakage. They're too common to be interesting.

https://news.ycombinator.com/newsguidelines.html

Most browsers have a reader mode that you can configure to your liking.

Pretty sure this is mostly unstyled html. If you don't like how it looks that's on you.

I find Dan Luu's blog extremely good to read on mobile, with great typography. The website also works with Firefox Reader mode and loads pretty quickly due to using the system's font.

If you're using Firefox, hit Ctrl-Alt-r and it looks however you want it to.

No. Line length and text wrapping restrictions are the devil. If you want smaller width text, resize your browser window rather than making a site that sucks for us who don't want smaller text width.