I agree on yes and no. If notation mattered little, there would not be that many different notations. Leibniz and Lagrange notations for derivatives, Einstein abbreviation for sums, Iverson notation for tensors that later became APL, or any language for any computer algebra system ever. If notation mattered little, inventing your own notation would matter little too.

But if notation mattered a lot then... there would not be that many different notations either. There would be one and only notation that works and no one would dare to divert from it.

Math notation is a cultural artifact with its own significance pretty much like SQL or x86 assembly language indeed.