Many people will be reading the pdf in their browser using the browser's js pdf renderer.
This is safer than running arbitrary js from the web, which most people also do.
So I guess most people won't worry about pdfs especially.
Is that why people care? I'm also old, and had completely forgotten how exploitable the Adobe viewers were for several decades.
Now that those links get opened in browser sandboxes, I assume the concern has diminished.
Nowadays pdf get opened in the browser in a javascript viewer that is sandboxed.
you say that like chrome hasn't had pdf vulnerabilities patched in their javascript viewer, but of course they have. This idea of just linking to PDFs and having people click on them seems like a bad idea.
Why is it a worse idea than providing links to HTML?
Your original comment is flagged, but I am generally wary of clicking on pdf links. Especially on mobile where I have to download and open in a different app. That's just a huge pain.
A PDF research paper on APA.org is pretty trustworthy.