Your comparison isn't very good as Microsoft Windows undergoes perpetual change and churn for the sake of doing it. This breaks existing workflows along the way. As a product it was effectively complete by the time Windows 2000 was released, having successfully integrated what was then considered state of the art technology to develop a practical operating system based on the principals known at the time. All it ever needed from there forward was maintenance updates and kernel updates to enable new hardware level technology to be harnessed by software.