Windows 7 is 12.9% of Firefox installs and the second most used OS.
I wonder how the analytics of Firefox forks are tracked. If they can even be tracked.
Tor Browser, LibreWolf et al privacy friendly forks, block Mozilla's data collection on startup and they spoof the user agent to Windows NT 10.0 regardless of if you run them on Windown 7, 8, 10 or 11.
Similarly, Windows 2000 and XP identify as NT5.0 and 5.1 respectively, and Windows Vista/7/8/8.1 identify as NT6.0, 6.1, 6.2, and 6.3 respectively.
Incidentally, this is also why drivers often are cross-compatible along certain Windows versions.
Formal drop is set to occur on New Year's 2024.
Just like in Windows 10 and 11.