Officially announced that from January 1, 2024, Steam will officially stop supporting Windows 7, Windows 8 and Windows 8.1 operating systems. After that date, the Steam client will no longer run on these versions of Windows. In order to continue to run Steam and any games or other products purchased through Steam, users will need to update to a newer version of Windows.
The latest features in Steam rely on an embedded version of Google Chrome, which no longer works on older versions of Windows. Additionally, future versions of Steam will require Windows feature and security updates that only exist in Windows 10 and later.
Official announcement: https://help.steampowered.com/en/faqs/view/4784-4F2B-1321-800A
