> There is not a understood natural phenomenon which we could not capture in math.

This is a belief about our ability to construct models, not a fact. Models are leaky abstractions, by nature. Models using models are exponentially leaky.

> I didn't say we can simulate it.

Mathematics (at large) is descriptive. We describe matter mathematically, as it's convenient to make predictions with a shared modeling of the world, but the quantum of matter is not an equation. f() at any scale of complexity, does not transmute.

I'm using simulate as a synonym for model. For any biological model at the atomic, molecular and protein levels, accuracy is key for useful models. What I'm saying is that accuracy at that level is a hard problem in computing and biology, and even simple protein interactions are hard problems.