Or the poll-bashing that happened after the 2016 election when an outcome with a 29% chance per one model was observed.
Any interesting forecasting problem is underconstrained. Monte Carlo methods are the classic way to mitigate that one-universe problem.
Nobody can predict the future with certainty. All models are wrong, but some are useful.
I fully agree that all models are wrong.
Their main usage is just replaying the past or encoding the modelers assumptions for the future.
But there is no way to know if a model is good or bad.
There would be if we had infinite universes.
1. No guarantee that the universe tomorrow will behave as the distributions you used in your Monte Carlo today.
2. If the universe stats serving you 10 unlikely events in a row, is your model model wrong, or just 10 unlucky draws? If your model was correct and you start "correcting it" based on these 10 draws, you now made it wrong.