There are around 400m W11 users so your numbers are not wrong.

The underlying issue here is the need for an OS at all. Many Windows XP machines are still sat around because there is one application the organisation needs or one piece of hardware. Whilst it is true you need something to make the computing parts actually come together how much of an OS is wasted computing?

Objects like Digital Cameras, iPods and Games Consoles are normally only designed to do one thing and don’t have an OS designed to do hundreds of other things. They also tend to work well beyond their expected lifespan.

To stop the rot we need dedicated workstations designed to do one thing ad infinatum.

https://www.windowscentral.com/software-apps/windows-11/exclusive-windows-11-is-active-on-almost-half-a-billion-devices-ahead-of-microsofts-expectation