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/

LibreOffice

LibreOffice is a free office suite

@neil similarly Windows has been essentially free for a few years but with ads. Come to open source! Linux, BSD, whatever floats your boat, no ads!