A peace conference in the early years, when the free world was avoiding war, might need different outcomes than a peace conference after a major war where the majors are willing to redraw the world map. Second, the first three to five years are crucial and even unique in themselves, not just for majors building up for the war, but also for minors who are trying to become a regional power and rearrange a border or two, before the big war makes almost any expansion a world affair. First, the game spans a short period of time.
As said above, HOI4 has unique needs for a peace conference.
