I agree that neural nets are state-of-the-art and do quite well on certain types of problems (NLP and vision, which are important problems). But a lot of data is structured (sales, churn, recommendations, etc), and it is so much easier to train an xgboost model than a neural net model. You need a very expensive computer or expensive cloud computing to train neural nets, and even then it is not easy. Ease of implementation is an important factor that gets overlooked in academia. And on non-NLP and non-image datasets, usually the single best Kaggle model is an xgboost model, which was probably developed in 1/10th the time it took to make a good neural net model. Xgboost has come a long way since it was first introduced, with early stopping being an example of a significant improvement.