When I get in front of a classroom and my tech isn't working, I call a number and they dispatch campus IT immediately to my location to fix it within 5 minutes. This kind of rapid response and support isn't possible for a department to fund, especially if it's a department like History.

Face it - students have higher expectations now, professors also have higher expectations. This requires administrative staff to run. Back in the day school budgets were lower, but even when I went to college in 2005 they didn't have campus-wide wifi in every classroom. We had one professor who taught with powerpoint. Today, every student has a laptop in class.

Maintaining a modern campus takes a big IT department and centralizing it is the least wasteful way to do things.

I was at a uni with departmental IT and I certainly could do that, I knew the 3-4 IT people by name and I could just message them and get whoever was on campus at the time to help me immediately if it was urgent.

There are things better done by a central IT team like university level WiFi, but you can make that smaller and also have departmental teams for things where more agility is needed. If the people are competent it's really great.

And yes 3-4 people only makes sense because it was a large department, but smaller departments with similar mandates, for example English/Literature and History, just have a shared departmental IT between them.