Predictions don't predict where it counts. The tails!
This goes back to Renaissance's emphasis on survival and hedges against risk of ruin as the number 1 rule for successful trading that almost no retail trader understands. After understanding this, they can safely make any prediction they want to make.
I am also saying that prediction is easier when you have signal. There is no signal in 30 minute data on intra-day, but signal emerges the farther you zoom out.
I think you're avoiding the mathematics like the plague. Survival and hedges are structured strategies. Strategies have shape, form and consist of numbers. Repeatable numbers are what constitutes prediction. If you have the shape, form and numbers that are repeatable, you have prediction. Therefore, the data you just analyzed is not random. If it was random, your outcome would be random. And it's not.
