Indeed, Excel is usually not the right tool. It is very powerful, but organization of the code/logic, correctness of the calculations, and readability/maintainability are all left on the developer. Mistakes are hard to spot. The levels of discipline and meticulousness needed to use the tool well are high.

I have at times remarked that typical Microsoft Office installations should exclude Excel! :-)

And I am saying all this about Excel even after being a power user myself and the primary author of the OP. :-)

Mathcad, Mathematica, etc. could be good alternatives if not Python or R.