> This leads to authors having to re-explain their thinking in detail, covering points that they’d omitted for brevity or because they are obvious to those with a good understanding of the problem.

IMHO there should be no gaps like that. If you already thought hard and long about these problems, why not just write all your knowledge down, so other people can benefit from that? Also, this makes your work a lot more accessible to those who came after you. Of course, you have to assume a certain baseline of knowledge. But if you already have a good understanding of the problem, why not formulate that as part of the RFC?

It is impossible for people to write all their knowledge down, there will always be gaps, there will always be things taken for granted.

The point is that the author thought that they had captured enough information in their original draft - they can expand on that draft of course, but that's the issue - the task of writing the RFC can become much larger than just trying something out and getting real data.