It’s the incentive structure, people! Why science reform must come from the granting agencies.
I discussed this same issue in Medicine sometime ago, if it were so that a solution is thought te have been found them the sampling rate should increase. This is a case of search satisfaction – you expected to find something found something so you stop searching rather than finishing your search. While in a larger sample set or more regression to the mean takes place, which means the results come closer to the average..