Microsoft is introducing ads into a free version of Office, which seemingly only lets users save to OneDrive.

In other news, LibreOffice is also free, doesn't have ads, and lets you save your documents wherever you want. I use it every day for my work. It is available here:

https://www.libreoffice.org/

Home | LibreOffice - Free and private office suite - Based on OpenOffice - Compatible with Microsoft

Free office suite – the evolution of OpenOffice. Compatible with Microsoft .doc, .docx, .xls, .xlsx, .ppt, .pptx. Updated regularly, community powered.

@neil The LibreOffice Suite also includes a very nice Spreadsheet application that does all the things, and a nice Drawing (think Visio) and Presentation (think PowerPoint) app. Been using these for personal and professional purposes for years.
All good enough when it counts, excellent in ways O365 is not.
And it does not snoop you. People made it that way.