Today's Confusion - Taiwan Railways

Taiwan Railways has a really rigid rule (??) (Regarding local trains) 1. If you arrive early and the next train is an express that's delayed, you're unfortunately told to wait until the express train arrives and departs. (I don't really get why you have to wait like this when it's already late.) 2. You have to wait for the express train to leave first. (This point is quite normal.) 3. If you arrive at the station early, you have to wait until the departure time to leave. (This point also doesn't make sense to me.) Why does Taiwan Railways, despite having its own lines like High Speed Rail, always get delayed so often? No matter how fast the train is, it gets delayed. When it's delayed, what's the point of the departure time? Is the schedule really just for reference?