The ease of adversarial collisions has no relationship to the probability of natural collisions. It's entirely possible to make a cryptographic hash algorithm

The ease of adversarial collisions has no relationship to the probability of natural collisions. It's entirely possible to make a cryptographic hash algorithm that has an exceptionally low probability of natural collisions but where adversarial collisions are trivial. It's also possible to create a cryptographic hash algorithm where occasional natural collisions are expected, but adversarial collisions require brute force.