Groupthink is very much the scientific method. According to Imre Lakatos the key question is does the group expand knowledge or contract it (very rushed reply as about to catch a flight)

In Lakatosian terms, the amyloid hypothesis is an example of a degenerating research program that has largely failed to predict new observations and is primarily driven by post hoc reasoning. The hypothesis was rescued by research claiming a significant new observation that was ultimately shown to be fraudulent (https://pmc.ncbi.nlm.nih.gov/articles/PMC12397490/).

From a Lakatosian perspective, the amyloid hypothesis is not necessarily wrong, but it is not paying off in terms of empirical insights relative to the amount of attention and funding it has received.

Proofs and Refutations is a great book

https://a.co/d/0cXTgHgv