The closed-vs-open model choice is a ceiling/floor tradeoff, not a quality ranking: closed APIs give a higher floor with minimal operational surface (no training, no raw data management), while open weights impose a much larger system (post-training, custom harnesses, robust data pipelines) in exchange for a higher ceiling. Ownership only pays off if the team can actually operate the additional stack.
It reframes 'should we self-host/open-weight?' from a model-quality question into a question of which operational subsystems you are willing and able to own, which determines team shape and infrastructure spend.
Any platform decision where a managed service trades away ceiling for floor should be evaluated by enumerating the subsystems you must absorb, not by benchmark comparison alone.
The closed stack is simpler (higher floor, lower ceiling) because you don't train models or manage raw data.
The open stack is like opening Pandora's box, requiring post-training, custom harnesses, and robust data pipelines.