Office has been available for Mac for well over two decades. There are so many more reasons for companies preferring Windows on the desktop than just Office.
[0] https://support.office.com/en-us/article/how-to-install-and-...
The only part of "Office" I really even use though is Outlook (at work), and it's pretty good at the job it does.
The actual problem is the lack of Group Policy support (or even a viable equivalent - preferably one that's cross-platform).