You have to put some effort in predictions and competitions as well before you can get the reward.
That's the rule right now, nothing is really free like in the past where Bitcoin can be obtained very easily.
Now it takes knowledge and skills to be able to get rewards.
Guessing the price is not just guessing but having to predict what the price of Bitcoin will be.
Luck can also be the cause of victory, but maybe only a few percent.
Nothing is completely free at the moment, just consistent knowledge and effort that gives you Bitcoin,
as I did on some art contests that gave me Bitcoin because of my chosen work.