This is a strange viewpoint, do you care to elaborate? I mean, for ancient Egypt, understanding the writing has its origin in a very clear, well understood event and a very specific researcher's career (Rosetta Stone and Champollion), after which there is a sea of research papers which anyone can go and (spend an education and career) judging for themselves. The documentaries easily skip all that but it's not a big mystery that "all that" is there?

It would be nice if someone created a video similar to the "distance ladder" video but for hieroglyphs. Beyond Champollion and into the progress to now. That would be fascinating. It may exist already.