I'll die on this hill.

Google Sheets was phenomenal for prototyping apps and getting quick feedback from users back when I used it in 2015-2020. Back then they had this janky implementation of Mozilla Rhino underpinning their "Apps Script" engine and it still beat the pants off of anything else you could use for free.

Certainly you can shoot your feet with the various spreadsheet-isms but if you're diligent about keeping raw data pure (preferably in a completely different sheet inaccessible to users) it does a bangup job of quickly shoving a UI in front of users and letting them realize what they want and iterate on it before calcifying it into a more rigid system.