The added value other than the stock market would be in making major life decisions.
In the case of the 2008 crisis, specific knowledge of the timing could matter for buying or selling a house.
In the case of technological predictions, specific knowledge of the timing could affect whether you want to take a university program in a given field or join a certain company.
If a predictor can’t help with picking stocks or making big decisions, then what are these predictions for, entertainment? Actually an HN comment on Dan Luu’s post about futurists really did suggest that futurists are practically entertainers.