Random thought: Windows is largely successful because of Piracy
Windows as a software package would have never been affordable to individuals or local-level orgs in countries like India and Bangladesh (especially in the 2000's) that are now powerhouses of IT. Same for many SE Asian, Eastern European, African and LatinoAmerican countries as well.
Had the OS been too difficult to pirate, educators and local institutions in these countries would have certainly shifted to Linux and the like. The fact that Windows could be pirated easily is the main factor that led to its ubiquity and allowed it to become a household name. Its rapid popularity in the '00s and early '10s cemented its status as the PC operating system. It is probably the same for Microsoft Office as well (it is still a part of many schools' standard curricula).
The fact that Windows still remains pirateable to this day is perhaps intentional on Microsoft's part.
Windows and Office were successful in enterprises precisely because they were popular and the familiar choice among staff. They got popular from piracy.
it's a bit disingenuous to think that corporations are using windows just because employees are familiar with that. Unless the work is only using a web browser, you need programs and stuff, you don't simply switch to Linux. Especially when "familiar with windows" for an average employee it just means "know where the icons are, and open Facebook in a browser".
A corporation would surely love to save $100k if they could just have a windows skin on Linux and force employees to watch a 1-hour video on training to use the new system. But then if they need to run [PROGRAM X]? and if they need to run [PROGRAM Y]? And what if some quirk of running [PROGRAM Z] on Wine introduces some bug that causes slowdowns and monetary loss?
They intentionally choose windows, and they will pay whatever Microsoft tells them because:
they can have support from less specialized (=cheaper) techs
they can control everything of their computers from a centralized position. If they want, they can force push the goatse image as the wallpaper on each single employee and nobody could change that.
it works well with the programs they use, and they are in a configuration that can be supported by techs
I think your third point is key, one thing Microsoft does very well is backwards compatibility. We run programs from the 90s in production. It is a nightmare of APIs layered upon APIs, but the programs will run.
Unless the work is only using a web browser, you need programs and stuff,
My employer is a sizeable tech firm that uses the Microsoft suite. The irony is that developers use WSL because the software they need are on Linux. We haven't switched to Linux just because the IT department doesn't know shit about managing a Linux fleet of devices. They haven't bothered to get the training/certificates because Windows is the status quo for big corps. This will stay this way until the next gen of sys admins form the majority, I guess.