Normal PDF's are simple, reliable, and interoperable.
In contrast to webpages which are actually more often the "clunky", "slow", "stuffed with fluff", and "disorienting" (with scroll hijacking) alternative.
But the strawman is people creating PDF content as an alternative to HTML. Practically nobody is doing that. Virtually every PDF out there is designed to be a printable document first, that is then made available on the web. Nobody is saying "how should we architect our new site -- I know, let's make all our pages PDF's!"
What a truly bizarre article.