The “scheduling” portion inside of your calendar is used specifically for making recurring priorities and for scheduling priorities in the future that you’d rather not have appear on your priority list immediately. For instance, say you had to work on a project 2 months from now and you didn’t want to forget about it. You could throw it on your priority list...but if you did that with everything you had to do in the future, your priority list might get really crowded and confusing.
We like to keep our priority lists as simple and as clean as possible. So being able to schedule items to hit our priority list down the road on a preset day is helpful for staying focused on what needs to be done today.