The so-called best practices are wrong sometimes. Or maybe they just talk about generic cases. In which case they often are wrong as well. Having the same code

The so-called best practices are wrong sometimes. Or maybe they just talk about generic cases. In which case they often are wrong as well. Having the same code twice can already be highly problematic if it is a longer stretch of code. It is virtually guaranteed that the two places start diverging and then the question is why. Is it because it actually needs to be different? Is it because a bug was fixed in one place that should have been fixed in the other as well but was forgotten?