A support model chosen once rarely gets revisited on purpose.
The first arrangement - a generalist hire, a starter contract with a support provider, or some of each - usually gets set early and then just continues. It gets judged informally: are people annoyed this week, did the last outage get fixed fast enough. That's a mood reading, not an evaluation of fit.
Meanwhile ticket volume and complexity rarely stand still. A model that worked for twenty employees and one office often quietly stops working at eighty and three locations, long before anyone frames it as a decision rather than a growing source of frustration.
Treated as a sourcing decision, the question separates cleanly: what does each model need to deliver, what does it actually cost in cash and in leadership attention, and what should trigger revisiting it - independent of which vendor or platform ends up running the queue.