Dividing stories into three parts is common. The ancient Greeks divided their plays into three acts. This tripartite division shows up in stories and plays from Henrik Ibsen to the fables of Aesop and the Hegelian dialectic (thesis, antithesis, synthesis).
I think the reason the three part structure lasts is because it forces movement in telling a story. The readers never stuck in one mode for too long. It builds pressure, then shifts, then resolves, which mirrors how people want life to work even if it rarely does. That structure gives stories a shape, and that’s probably why we keep coming back to it.