I've been working on a spreadsheet which is more amenable to embedding in programs (compiling to an IR which can be translated to high level languages or [eventually] compiler IRs like those of LLVM or GCC). I worked at a company where months were spent recreating models from a spreadsheet produced by subject matter experts, and this was a major cost.

A spreadsheet optimized for integration into software build processes would probably create more than a billion dollars of real value every year with even limited adoption.

While it may be true that Excel is overused, I believe that the spreadsheet is chronically underused as a model for software development.