Choosing to structure enterprise deployment as a separate venture rather than an internal department has justification beyond accounting.
A product company hires to build one thing many people use; a services company hires to solve one client's specific problem at a time. The two activities require different temperament, pace and success criteria.
Mixing them in one structure usually fails at both ends. Product builders get irritated by client-specific requests; service providers get frustrated when the product roadmap ignores what they found in the field.
Separating also protects the financial read. Service margins are lower and growth depends on hiring people, which spoils the indicators the market uses to value software companies.
For technology service providers, that separation by the largest players validates the model: they concluded deployment is its own craft, not a natural extension of making the tool.