At least the OP excerpt focuses only on Ford’s efficiency engine: precision machining, interchangeable parts, and the moving assembly line combined with extreme production volumes to make the Model T nearly impossible to compete with on cost and reliability. But there’s a deeper lesson than just “Ford was rigid, GM was flexible.”
The real dynamic was that efficiency and scale compound improvements but also compound lock-in. The more Ford optimized his system around one product, the higher the switching cost to change anything fundamental. Every special-purpose machine tool, every supplier contract, every material flow was tuned to one car. At small scale, that’s agility. At massive scale, it’s a straitjacket.
Tesla faces a version of this trap. Its efficiency engine is vertical integration and battery/powertrain mastery. But the stronger that engine gets, the more risk that its identity collapses into “this is what we make, as efficiently as possible,” rather than “this is what the market wants, however we must adapt.” GM in the 1920s wasn’t just adding variety for fun, it was creating a systematic upgrade ladder (“a car for every purse and purpose” as Sloan said at the time) that turned consumer churn into a growth engine (allowing customers to start with basic models like Chevrolet and progressively upgrade to more luxurious brands such as Oldsmobile, Buick, or Cadillac). I agree that Tesla hasn’t yet built an equivalent mechanism to capture customers once they’ve “had enough of the Model T.”
The irony is that efficiency-driven firms almost never stumble because they stop improving; they stumble because all their improvements are local optimizations. Ford’s engineers in 1925 were still making operations faster, parts cheaper, and tolerances tighter, but all within the cage of the Model T. Tesla today is in danger of repeating this exact logic trap: world-class at batteries and drivetrains, but perhaps blind to the fact that consumer perception, design novelty, and product line evolution can erode even the strongest cost advantage.