The linear assumption I'm referring to is forwards-looking not backwards-looking. Up until say last year I think the consensus was that a production-deployed FS

The linear assumption I'm referring to is forwards-looking not backwards-looking. Up until say last year I think the consensus was that a production-deployed FSD vehicle was ~5 years away. It shipped this year for both Waymo and Cruise. Unless you're arguing that the pessimists and optimists have just been arguing over the slope of the line, not the curvature (which may be fair.) If that surprise is any indication it leads me to think a similar consensus-breaking event may happen with Tesla, but time will tell when that is, since as you state they are behind in several ways.