What it was for
The back half of Design Thinking managed expensive exploration. Brainstorms widened the option space because options were costly to produce; prototypes were deliberately rough because fidelity was expensive; "fail fast" was a budget instruction wearing an inspirational costume.
The verdict
TRANSFORMS. The inner loop produces working prototypes at the cost the old world paid for paper sketches — the prototype and the product converge into the same object at different stages of verification. What was a generation problem becomes a curation problem: the scarce act is no longer producing thirty options, it is having the taste to recognise the two that matter and the discipline to kill the rest.
What changes
Workshop design inverts. Divergence is partially delegated to the machines; convergence — the genuinely hard half that facilitation traditions always under-served — becomes the human centrepiece. Fidelity stops being a virtue signal in either direction: you prototype at whatever fidelity the question demands, because all fidelities cost roughly the same.
The strongest objection
Roughness was load-bearing: a sketch invites critique, a polished build invites acceptance. Conceded, and the finding survives the shift — teams must now choose roughness deliberately as a psychological instrument, where the old economics imposed it for free.