It's true that what you say is that there are no 100% accurate predictions, it's just that perhaps by predicting them we can understand a little of the developments that are occurring.
It is too difficult and I can say that would be at a stage of impossibility that we can think that prediction would be 100% accurate. As we have also seen that 100% in some cases even but this also included some luck, just like an example as you are playing a dice game in which you assume there would be 6 sixes then it comes true then we all would sure it includes some luck in it.
Same in the case here, but the technical analysis of the people are so strong the in the trading not all but some of the traders who have studies the coins and they have even all the information about the graphs of the coins. But still the may fail at some points due to the market up and down. So I didn't fully believed in these things like following them on different occasions.