Answer:
Down below.
Step-by-step explanation:
Well, they kind of aren't, in my humble opinion. But this is what I can think up on the spot if you really need reasons:
1. They help bring the community together. Assemblies are times for bonding where the entire school can be in one location and have no barriers.
2. They allow for updates on current events both internal and external to the school. This is crucial for being aware of one's surroundings at a given time.
3. If for nothing else, they are routine and a tradition among many schools - they may help scheduling discipline and a routine cornerstone in students' and staffs' days.