The current Model S received its last major update about three years ago. This refresh brought significant architectural and structural improvements. Lars mentioned that this update was "bigger than most people thought" in terms of the underlying architecture.
Despite being Tesla's oldest model in production, the Model S Plaid remains incredibly competitive in the market. As Ryan McCaffrey notes in the interview, it may still be the "best overall car in the world" in terms of price performance, range, safety, and utility.
For under $100,000, customers get a vehicle with rocket-ship acceleration, long-range, and premium features. However, it lacks some newer technologies that have appeared in Tesla's more recent cars.