This isn't a question more a discussion but the prophets attack on earth was actually instrumental to winning the war Now you might think, " how earth is humanity's home world that just shows humanity is losing blah blah blah" but actually if they had never attacked or never been interested in forerunner tech humanity would be extinct The projects were looking for the portal to the ark, which was in Africa. When it opened all cover forces went through the the portal ( there may have been a few left behind but they would have been killed by unsc) when chief ignited installation 04b it killed all covenant and flood there, thus ending the war