People can fool themselves, hallucinate, and even go insane.

This is the key point - when people have crazy moments then compared to non crazy moments they are more likely to make extreme claims, and this is what makes it reasonable to be skeptical of extreme claims.

Academic communities can also have crazy moments, which is why we should be more skeptical of extreme published claims.

Given your emphasis on replication, it becomes extremely important to evaluate how an academic field actually practices, rewards and interprets attempts at replication. They may give lip service only.