As others have pointed out, you should be able to adjust your browser to get the reading experience you want. Turn your tablet vertically if reading in landscape. Open current tab in new window and make it as narrow as you want. Or have smart browser extensions that do it automatically for YOU.
Browsers used to have controls to toggle CSS stylesheets on or off. Frankly, I'd prefer they still did.
> javascript:document.getElementById("hnmain").width="50%"
javascript:(function(){document.getElementById("hnmain").width="50%"})();
I'm not sure if HN will accept the link:
<a onclick="alert('Drag this link to your bookmarks bar'); href="javascript:(function(){var body = document.getElementsByTagName('body')[0];var style = body.style;var ss = [55,34,21,13,8];var sx = ('bodyMaxWidthIndex' in body) ? body.bodyMaxWidthIndex : 1;style.setProperty('max-width', ss[++sx % ss.length]+'cm', 'important');style.setProperty('line-height', '1.5');style.setProperty('margin-left', 'auto');style.setProperty('margin-right', 'auto');style.setProperty('font-family', 'sans-serif');body.bodyMaxWidthIndex = sx;})();">→🖺←</a>
Maybe add in the trendy color: #222.
Or you can resize your window?
So no: failing to set max width on a web page is not a good way to just present a clean page of information rather than an experience. It's just a bad webpage.