> I have never met a single person in my entire life who likes using Windows. Everyone I know claims "yeah it's crap but this CAD/Industry standard software works only in Windows".

If this is not a walled garden, I don't know what is. Linux is certainly not a walled garden.

In computing, a walled garden is a closed ecosystem controlled by the platform owner.

None of Windows, macOS, or Linux are walled gardens because all of them allow anybody to publish software for those platforms. You don't need approval and you don't need to distribute through a central authority.

iOS, on the other hand, can only load apps from the App Store and that store only carries software approved by Apple.

What you are talking about is proprietary software. That's a different beast.

Maybe you are right in terms of strict definitions, but in reality the proprietary software effectively creates the walled garden from which the users can't escape.