But how does it make sense in the case you describe to hide those pdfs on the site so deep you cannot find them except when told where to click (or by major accident)?
I'm kinda lost, in another comment you mention the Eket system, so if it's those components you're looking for there's a full page for them liked right at the top of the Eket page:
If we're talking about the "Product details" -> "Assembly and documents" part, that's 3 clicks away and looks pretty straightforward to me. You make it sound like it's 15 levels of links inside the privacy policy.
that contain all information about series in compact, easy to understand form. Try finding that pdf on their site. Now imagine chances of finding it for someone who is not aware it exists. All it would take Ikea is adding one more pdf to the "Assembly and documents" section, so why hide these so much?