I am the developer of xlwings, so this is heavily biased. Anyhow, ever since I’ve added support for Google Sheets, I am building all internal tools with it. No

I am the developer of xlwings, so this is heavily biased. Anyhow, ever since I’ve added support for Google Sheets, I am building all internal tools with it. No HTML/JS/CSS required whatsoever and everybody knows how to interact with a spreadsheet UI. There are a few sample projects on GitHub, e.g., https://github.com/xlwings/xlwings-googlesheets-pandas-plots https://github.com/xlwings/xlwings-googlesheets-pandas-plots (they use FastAPI, but it’s trivial to adapt for Flask). On top, Google Sheets let you easily authorize the user on the backend, so you can give certain users read-only access to a database, as an example.