There were the same questions previously:

- Ask HN: What do you use MS Excel for? (2018) - https://news.ycombinator.com/item?id=18130552

- Ask HN: What do you use Google Sheet or Excel for? (2020) - https://news.ycombinator.com/item?id=24261447

I recommend you to check these out. Hopefully, it can give you the idea/inspiration.