Asking for advice on whether to get an interrail pass or pay for individual trains.

Me and 5 of my friends(20) are going travelling through mainland Europe in early to mid June over 15 days, and have been debating whether we should pay for all the trains individually or buy a pass. We are all English and are flying in and out.

The trip is ZAGREB - LJUBLJANA - LAKE BLED/LESCE BLED - SALZBURG - PRAGUE - BERLIN, spending 2-3 nights per place

Adding it up, individual trains seem to be significantly cheaper, especially if we sprinkle in some buses, but the interrail pass seems more flexible. Is individual train booking more stressful and feel more time restricted per area? We are uni students so want to keep a relatively low budget, but also enjoy the trip.

Hoping for some more ways to think about this to hopefully sway us one way or the other.