I think it’s safe to say that replicating published studies will almost never perform as well as the published results. Sometimes they will outperform the benchmark but not as strongly. Sometimes they won’t outperform at all. One might think that the easier the study is to replicate, the less likely it is to outperform, due to the nature of investor arbitrage. However, factors that are rooted in human behavior or mathematical laws are much more resistant to being arbitraged. So, for example, there are many studies that show how value and/or momentum strategies have worked in the past, and because those factors are so deeply rooted in investor behavior, I wouldn’t be surprised if they kept working for a long time even if they’re relatively easy to replicate.
You might want to read the following blog posts, which discuss this in different ways: