How to create hyperlinks between distinct Keynote docs?

jtwittbold wrote:

clearly the Apple Notes product team supports links between "Apple Notes documents" (i.e. between notes)... why not support Wiki-like links on the grounds of overall product enhancements to the Apple productivity suite?

No one here in this user-to-user forum would know "why" Apple does or does not do something. You can, however, let them know what you'd like to see here:

Product Feedback - Apple

There are no hyperlinks between Apple's Pages, Numbers, or Keynote documents. That is an Apple design consideration and any reasoning behind that decision is private to the respective Apple product team — who do not participate in these fellow user supported public communities.

If you need interapplication document linking then you should be using Microsoft Word, Excel, and Powerpoint.