The decision is cultural, technical, and procedural
The first line is cultural. It comes down to how much control your organization needs to hold, how well it handles change, and whether leadership will sponsor the work out loud, which the Prosci data shows is decisive. An organization that will not let go of control will struggle with a managed model, however good the technical fit. One that has no appetite to run complex operations will struggle just as much in-house.
The second line is technical. It is the complexity of your environment, the regulatory load it carries, and the migration burden ahead of you. A simple, stable estate is far more viable to run in-house than a multi-cloud environment under strict compliance obligations with a platform transition already on the horizon. The heavier the technical load, the more the offload of a managed model earns its cost.
The third line is procedural. It is the Day 2 capacity you have, the maturity of your operational processes, and the governance already in place. This is the line teams misjudge most often, because capacity on the org chart is not the same as capacity that is free. Reading these three lines clearly is the work, and it is easier to do with the environment in front of you than in the abstract.