I think I agree with the explanation, although the question does split hairs. Google Workspace was positioned to provide those services. While Microsoft does provide web-based productivity solutions, Google was doing far earlier than MSFT was, which was its original intent. Originally, Office 365 distributed desktop Office - web Office came a bit later.
So it might be seen as 'six in one hand, half dozen in another, but Google never positioned its productivity apart from SaaS, while MSFT's original intent was not SaaS.
IMAO, that is.
/r