A bank in Belarus scrapped ML model that was used to issue consumer loans after a year. Initially the model gave better returns, but after a year it was underperforming. The bank went back to a weighted average of few factors like it was before with humans reviewing the weights. In retrospect this is not surprising. The model tries to predict long-term behaviour, but besides few stable factors like profession, income, education human life still rather unpredictable even after averaging hundreds of thousands cases.