Yes, I would agree that technical and non-technical usability is one appealing spreadsheet use case. I think that another thing I find myself using spreadsheets for is simple data entry. By using a google sheet to enter data, you've already got yourself an authenticated, multi-user web form for easily entering data. It even integrates with google forms, which is a very handy tool for collecting data. It's certainly a lot easier than building it all yourself and hosting it.

Once the data is entered, there are much better tools for data visualization and aggregation (in my opinion). It's nice to have the "frontend" taken care of so that your time is freed up to analyze and extract meaning from the data. I'm speaking from the perspective of someone who does a lot of rapid prototyping and data analysis. There are likely use cases where this won't scale.