Yup, I have. And had to deal with converting "this awesome tool that does X, Y and Z" to an actual multi-user app because it was just so great. You end up discovering that there are tons of miscalculations in these formulas that only surface when you start writing tests for them, and that a lot of the business decisions based on these tools had flawed assumptions.

Having said that, I love that Excel has democratized app-building and made it easier for people to solve their own problems. In terms of alternatives, I think it's more about the UI and mental model that people have when using Excel, not necessarily the functionality. There may be 1-to-1 competitors in terms of functionality, but in terms of UX, Excel is sort of king.