Vlans vs router on small network

Hi guys

I am designing a network for fictional IT college in packet tracer as part of my assignment. I have most of the design done and functional however I'm hesitant on one thing - routers vs vlans.

I have a router connected to the main core switch which distributes the network across the LAN and other switches in each department. I have created vlans with the idea of securing the network based on user access such as staff, student, guest and IT management, however, I'm wondering if those 4 vlans is enough or should I also add routers in each department?

Vlans do the job for my already as I'm able to route specific traffic where I want to. What would be the benefit if I also added a router in each department?

Is there a point in doing this?