Whereas Apple built their 700M from nowhere (near bankcrupt sub-2% market share in 1997, starting building their subscription offering past 2007, and more seriously, past 2012 or so).
Word is more debatable. Yes, if you use it just for taking notes or something, the alternatives are fine.
But if you want to make a nice-looking document, Word is still just a lot better. I've never seen a fantastic Google Doc, for example, even that my company's designers have worked on.
And LibreOffice is another, older generation of UI/UX that is far behind Office at this point.
There is no program called Office.exe. Microsoft Office is not a single business product; it is a suite of products.
A product is not necessarily a program (an executable).
A suite can be a product too, and you can absolutely sell a suite as a single SKU.
In fact that's exactly what MS does 90% of the time, and it even used to sell it in shrink-wrapped box form.
The comparison is certainly apples to oranges; just throwing it out there that 700M across a range of consumer offerings isn’t that crazy when a single business product can reach 300M.