Even that won't last forever. Notably, Edge is only guaranteeing updates until October 2028 [1], coinciding with the end of Windows 10's 3-year ESU period. Previously, Chromium ended support for Windows 7 at the end of its ESU period (which was also the end of support for Windows 8.1) [2]. However, Firefox continues to support Windows 7/8.1 by providing security updates for an older ESR version of Firefox 115; they appear to be re-evaluating whether to continue support every 6 months, currently set to end in March 2026.

[1]: https://learn.microsoft.com/en-us/deployedge/microsoft-edge-...

[2]: https://support.google.com/chrome/thread/185534985/sunsettin...

[3]: https://whattrainisitnow.com/release/?version=esr

I have patched Firefox 115 to run on XP, so no doubt it would be much easier to continue doing it for something as new as Win10.