"Statistical" randomness can exist. But "True" randomness as some have stated is logically contradictory. What one implies with it is acausality, that identical conditions or premises(down to the most basic level) will yield at least two or more different outcomes which can even be contradictory to the other possible outcomes.
Acausality can exist in terms of the existence of truths being atemporal, without cause, but it cannot exist within said truths. The starting premises or conditions cannot yield different and possibly even opposing conclusions that contradict each other(This only occurs in human arguments, because there exist unstated assumptions that change the conclusion derived from the data... but if we were given all the assumptions, which are additional premises, the conclusion would be one.).
When it comes to the past we do not say that there are probabilities, there are only certainties. We say the probability becomes 100% after the fact, but this implies that there is a qualitative division between past, present and future. If we assume no qualitative difference exists between past, present and future, we must assume that both the present and the future are as determined as the past, and thus are
https://www.physicsforums.com/showpost.php?p=2384967&postcount=24".
PS
As for quantum uncertainty, besides the hidden variables very real possibility. I've heard( in some articles) that it is theoretically possible , using some of the same quantum unintuitive phenomena, to device a method that can have some probability of detecting some aspects of something without disturbing it at all( quantum-mechanics interaction free measurements). If this is not false , it would suggest to me that even though it is a very low probability if similar methods exists(that have not been discovered) that allow measurements of other aspects without disturbing, it could be possible to measure multiple aspects of something at the same time and get a result without disturbing it.
The only thing that would impede this would be that the first premise is false(this type of measurement is impossible), or the second one(there exists no way to measure other aspects in this way).PPS
Another example would be that of pseudorandom number generation, just like pseudorandom numbers any sequence that lies in the past becomes predictable if it reoccurs in the future. Thus it is no longer unpredictable. If we assume the future and present are qualitatively no different than the past, we see that it too must be as solid and as determined. But not only that there will, given infinite time, always exists an infinity of future observers, such that all possible finite sequences lie in the past relative to some future observer, and thus are all in principle predictable.
The only way this would not be is if time is not infinite or the future and present are qualitatively different from the past. Then we'd need a mechanism that transitions and qualitatively changes states from future to present to past. What mechanism could this be? And what would it be doing, creating the present based on the past? Choosing amongst parallel possible futures? What would it be doing?, and how could it operate?, as this mechanism must be truly random it would have to be intrinsically so and it would also have to deal with the fact that time passes at different rates for different observers yet we all share the same causal world.