Spreadsheets are the killer apps. Since I became pointy haired sheets and documents are the fuel of most what I do. Even things like Jira we use them only for the bare minimum and we refer to sheets to see how things are going. Not that I think it's sane, but it's what works.

I even have done this first day's advent of code, and the first part of day two, in a Google sheet. Formulas only, so no scripting needed.