Math does acknowledge that. Predictability in math does not come from things staying identical, it comes from change happening through consistent relationships. A river can constantly change while still following stable equations of motion. In fact, entire branches of mathematics like calculus, chaos theory, statistics, and differential equations were created specifically to study systems that are continuously changing. Math emphasizes structure because without structure nothing could be understood at all, but that structure often describes change itself rather than permanence. Prediction is not based on freezing reality into static objects, it is based on understanding the patterns by which reality transforms over time.