Windows 7 is one thing and browser is another.
It is the COMBINED decisions of Mozilla and Discourse that create this stupid limitation.
@teslasystems
Try a "special" build:
https://msfn.org/board/topic/186741-firefox-and-chromium-running-on-windows-7-by-e3kskoy7wqk/
Besides their utility, projects such as this one (OT, but I am using this forum from XP using Supermium browser) clearly show how there is not any technical, real, limitation, it is just the developers that don't care about people using older Operating Systems.