> In particular, even treatments that directly reduce amyloid-β in the brain did not restore cognitive abilities.

Correct, but this doesn’t constitute “fake data”. It could be that amyloid-β is a marker rather than a causative factor. Or it could be that amyloid-β related damage is downstream, and remove amyloid-β after the damage has been done won’t remove the other damage.

It’s too quick to wave away an entire field because a single theory didn’t pan out. Most medical research proceeds with a lot of dead ends before it is figured out.