Most office environments seem to be using OSX for their client OS these days. It's just much more behaved OOTB. The only thing people really need Windows for now is the domain controllers and goofy legacy embedded stuff.
But, there's a lot of business software that's locked into the MS ecosystem with Active Directory.
Office365 is de rigeur.
Then there's everything built on SQL Server.
Excel is the "bicycle for the mind" for many types of professional.
Heaven forbid you ever have to work with an IE-only app from 2003, but those still exist in the wild.
I dream of a glorious shining day when all computing will be 100% POSIX-compliant.
Said as someone stuck on a windows machine with all of the corporate monitoring spyware which makes performance crawl.
I'm also starting to see a lot of Macs pop up in smaller private practices - most dentist offices around here are on Macs, a few dealerships have moved over, etc.
Windows is still the majority by far, but its marketshare is slowly being eroded away. It'll be a while before F500 enterprises move over, if at all, but small-medium businesses are definitely growing their macOS usage.