> Underlining is an emphasis hack for mechanical typewriters or in handwriting. There's no reason to use it typographically in something which has all the layout possibilities of a modern computer or printer.
The argument presented by that link is valid for paragraphs and valid for printed content.
On a website, underlining single words or short phrases doesn't make them less unreadable, it draws attention to them.
Like with hyperlinks; the displayed form of `[See here](http://here.com) for more inform` is undeniably better than simply `see here for more info` and leave the reader guessing which of those words is the text and which is a hyperlink.
The problem is exacerbated on mobile where the reader cannot hover a mouse over the words to determine which words are a link and which are not.
If you're writing a full paragraph like this:
"Our previous stories of FooBarFactory Inc were well-received by our readers. Investigative Journalism has always been a core principle of PotatoNews. The images and video that our beloved readers shared on Twitter are only a single component in the fight against big corps polluting our environment."
In the above paragraph, "previous stories" is a link, "FooBarFactory" is a link, "well-received" is a link, "images and video" is a link, "Twitter" is a link and "Polluting out environment" is a link.
The advice from Practical Typography would render that entire paragraph free of any indication that there's more for the user to read.
