Windows 7 ISO images are available for everyone to download. It can be because they are now used to it, or for any other testing purposes.
However, even in this day and age, some people still prefer using Windows 7 for their daily tasks. It has since been superseded by Windows 8, 8.1, 10, and Windows 11, and the support for Windows 7 ended in 2020.
Windows 7 was first released on 22nd October 2009.