I see that too on Statists for example, which doesn't state a methodology that I can see but I suspect it's users (every Gmail account?) or 'I have used Docs/Word365'.

This site claims Office365 absolutely dwarfs Google Workspace in # business customers/licences , which is more in line with my expectation: https://www.bybrand.io/blog/market-share/amp/

That sounds about right. I routinely dig through cybersecurity data from around 100k companies, and Microsoft has no real competition. Occasionally I see Google at a little 500-person up-and-comer, but almost never in the enterprise, and they show up less and less as the companies get bigger. I don't think I've ever seen them in the Fortune 100, for example, other than at Google itself. The world runs on Exchange and Office.