I think the best approach in many cases is to bring data management into a specialised application, rather than using spreadsheets as a database. They can use the CRUD applications we all write or some off-the-shelf solution, but the important thing is that it provides validation, schemas etc.

Then you provide a spreadsheet export or direct connection that can be hooked into another spreadsheet with all the formulas, pivot tables and so on.

This way the core data is safeguarded and kept clean while not requiring constant development for every report requested.