What are the main takeaways we, as statistics community, learned from (time series) competitions?
Kaggle, or the M.. competitions, seem such a valuable source, but the (only) main insight I remember is that boosting algorithms such as LightGBM or XGBoost tend to work very well. I am currently teaching a course on practical machine learning and want to tell the students the main insights gained in time series modeling in the wild. I am also wondering whether it still makes sense to talk about the theory behind ARIMA, for example (depending on whether the algorithm is still competitive in practice).
Before raising this question, I had a look at the conclusions of the M5 competition, but some of the key takeaways, such as Exogenous/explanatory variables were important for improving the forecasting accuracy of time series methods. seem rather trivial. What I am looking for is a kind of meta-study aggregating the results of different competitions.
Btw, this is (surprisingly) the only related question I found here.