Repetition or iteration is fundamental to mathematics. Symbolic mathematics is iteratively applying axioms and schemas to elements of a language. Computation is iteratively applying rules or functions to sets. The correlation between numbers and iterations is strong; zero iterations is identity, one iteration is the unit of computing/application/doing-something. More iterations yield ordinal numbers, and there we are at numbers being inevitable.

In theory a universe could be entirely continuous with no need to "compute" in any discrete steps but quantization in our universe suggests that numbers also have a place in correspondence to quantized aspects of reality.