The whole amyloid hypothesis is a bunch of crap and a perfect example of one facet of contemporary horrible science.
Sometimes I feel like I am being mocked. In school they teach us about hypothesis based science and the moment you have a degree everyone preaches publication based science.
Go with the flow and ride the waves, they say. And you end up with billions fail invested and no step forward.
What annoys me the most is that the scientists that pushed the narrative are still pushing it. "it has to be right", "the others did it wrong"...
You had your hypothesis, you tested (echo chambered) it, and the result is NOPE.
Wrap the shit up and go to the next possible hypothesis. Rinse and repeat.