The number zero wasn't itself the big thing, it was the introduction of a positional numeral system, which needs zero to represent quantity in a given position,

The number zero wasn't itself the big thing, it was the introduction of a positional numeral system, which needs zero to represent quantity in a given position, so you can note numbers such as 101 to mean "one hundreds, zero tens, one ones") Many cultures had at least a word for zero/nothing in the context of numbers, but didn't have a positional numeral system, and in many cases didn't have a numeral notation for it either.