> Honestly, my problem with the video in question is that its tone unjustly attempts to denigrate Feynman (starting with the clickbaity title itself, a sham legacy? really?) by trying to frame the narrative that his supposed works were not his to begin with.

The video is not about denigrating Feynman. The "sham" legacy refers not to Feynman's legacy as a physicist, which is undisputed. The "sham" legacy refers to Feynman's false legacy written by other people for personal motivations.

> The comments in that video validate this sentiment to the point that people joke about him not existing at all?

Yes, that's the joke, but you're misunderstanding it. The joke is not punching at Feynman, but about how we know so little about him because we have no written primary sources about his views, only secondary sources.