Is it not though? It's not a guarantee but definitely an indication.
It’s a mistake to assume that there will be 100% correlation between the past and future, but it’s probably as bad of a mistake to assume 0% correlation. (Obviously dependant on exactly what you are looking at).
So while the odds at the extremes are low, they cannot be ignored.
No one can predict the future. But those that assume tomorrow will be like today are - per history - going to be fatally wrong eventually.
Each circumstance is different. Sometimes the past is a good guide to the future – even for the notoriously unpredictable British weather apparently you can get a seventy percent success rate (by some measure) by predicting that tomorrows weather will be the same as todays. Sometimes it is not - the history of an ideal roulette wheel should offer no insights into future numbers.
The key is of course to act in accordance with the probability, risk and reward.