1. Expectations on the flow of information, whether the author/presentor is:
(a) the authority figure, is teaching something to the audience and later answering questions or offer clarifications, but may also receive counter-points and feedback.
(b) presenting their current thoughts and looking for feedback on the same to refine their thoughts and plans.
I see no reason why 'b' isn't doable with slide-presentations, and we have actually done that more frequently than 'a'.
2. The container, slides vs. document, in which the information is presented. We are agreeing that slides require being more crisp, which is hard, owing to expectations of less text. Whereas a document also should ideally be crisp, however, expectations of use of a larger number of words and fuller sentences makes it easier. You have stated that the information for "kinds of problems that require document writing" and "topic, trade offs, solutions while supporting evidence or technical details, design artifacts, and FAQs" cannot be put into slides, but without explaining why so. I am questioning this again because I and my team has done all that successfully and repeatedly.
3. Sync vs. async. consumption of #2 by the audience. Even information put in slides can be shared with the audience for a silent consumption before discussions, and also be referred to later if and when needed.
## The real challenges are:
A. The popular guidance given for slide-presentations is to keep text on the slides to a bare minimum and have the focus instead on presenter speaking during the meeting. This makes things further worse as the slides by themselves end up being uninterpretable without the presentor speaking. Or in other words, the slides end up being little more than speaker notes. I generally disagree with this blanket guidance, and have used slides in both ways:
(a) Everything I need to communicate to the audience is written and visible on the slides, and I am peripheral to the meeting (think of a Teaching Assistant as opposed to a Lecturer), and
(b) The slides carry just the visuals which I explain live verbally.
Both 'a' and 'b' have their place depending on the context, i.e., the subject matter, audience, expected flow of information, etc. As an example, 'b' is more useful for classroom teaching to kids or otherwise for an audience who are averse to reading (there are many of them outside of work).
B. Use of slides require bring crisper, which we're already agreeing to.
C. Slide-presentations are typically done in sync manner under the status quo (but which need not be as noted in '3' above). The analog for documents would be to have all audience read section-by-section or para-by-para and discussing before proceeding. Whether applied to slides or documents, this is more useful only when the material has a sequential structure, i.e., the next section cannot be understood well or agreed upon until the current one is. Even if such sequencing is not there, sync does not always hurt though. Sync will be less optimal if:
(a) The material is somehow such that the readers must go back and forth through the material before they would understand that the author is communicating. Too much of that won't be recommended for documents either.
(b) When different audience members have widely varying (i) prior knowledge or understanding of the material, (ii) reading/absorption speed, or (iii) interest level in the subtopics or detail. Under this scenario, synchronization is at least one of ineffective or inefficient. Going fast would save time for those who already know, absorb fast, or want to skip subtopics/details, while the others would fail to follow. And vice versa. The said variations apply to document reading also, however, async consumption allows some audience members to finish sooner and then do something else while the remaining finish reading.
## Summary of my understanding
If we do not conflate various above points, we'll find that it's not about document vs. slides. The real problem are 'A' above (bad guidance on how to make/present slides) and 'C(b)' above (cited variability in the audience). Between the two, 'A' is more easily fixed by changing guidance and training. Then using slides with silent reading becomes an available option for 'C(b)' too, except for the challenge 'B' above.
If the authors have the skill for 'B' above, then not only slide-presentations, but also documents will be a lot better. So would also be meeting summaries which usually don't have the vigour/quality even at Amazon.
## Closing comments
Please think through the above carefully and then tell me what you think. I am open to debate. :-)