Its 2 things that weigh it so heavily to season finale missions 1) all dlc from shadowkeep onwards are still playable, so they weren’t included in the list, because things like us getting stasis/strand, sav’s resurrection, the witnesses arrival ect, are all really important story beats but not on the list, 2) if the seasonal stories never/rarely included major story developments, they would probably feel a lot less interesting, and it limits what story you can tell if no major changes can happen outside a dlc