PC sales are down a lot (mostly due to Win 10 being a bag of nails that tries to advertise and sell your soul). Most have moved to tablets and mobile phones, Mac's and Linux machines. Your Mac figure is clearly wrong - get on a train and look at what people use. Go to a university or college and watch what student have. Go and work in a corporate with a BYOD policy and count the number of Mac's vs Windows Laptops and Linux machines used.
Most enterprises are delivering a lot more on Linux servers rather than Windows based platforms, but many are stuck (for the moment) on Windows PC's due to the software legacy, but virtually all modern apps are web based, so the dependency on Windows and Windows desktop is being eroded all the time - as people (including those with very large corporate budgets) are fed up with it..
In regard to reliability, it depends on what you are measuring, focusing on the topic here which is activation, can't recall a single event where any Android, Mac or Linux machine decided to deactivate licences on a global scale, Windows has counted two now, One last year for Windows 10, one this year for Windows 7.
Broadening it out to all reliability, Windows has had an atrocious record in recent years compared to the competition. Virtually each week there is a major problem or something that worked yesterday is borked due to the forced update - with an ETA for fix being several weeks or months out,.
I've not seen that on Mac, Android or Linux to anything like, mostly as they let the user when to update. Apple is not perfect but even they test things to minimise impacts and react fairly quickly when things go wrong.