I recently read the following article https://www.quantamagazine.org/researchers-identify-master-problem-underlying-all-cryptography-20220406/ which links to https://arxiv.org/abs/2009.11514 that proves that the existence of one way functions is equivalent to the time-bounded Kolmogorov Complexity being impossible to compute in polynomial time for a certain fraction of inputs.
But it seems to me obvious that it is impossible to compute time bounded Kolmogorov complexity K without running (or at least checking) all programs of size less than K, of which there are an exponential number (since how else would one know that a program does not output a string x in t(x) time?) so it should always take exponential time to calculate time bounded Kolmogorov complexity. This would imply that one way functions exist according to the authors.
Clearly this was not obvious to the authors of the arxiv paper or the authors of Quanta since they didn’t mention it. My question why don’t people think this is obvious?