Look at the automobiles from the fifties, with all their curves, and then by the seventies they’re all boxy.
But it still doesn’t make sense.
1950s cars are all curvy, 70s they get more boxy.
But why is it that all the “1950s” ships in the PT look like they just got driven off the lot, while the “1970s” ships in the OT look like they’ve been around for more than 20 years? They’re all dirty, and worn-in.
It doesn’t seem like a natural progression in technology because if that’s the case, why does all the starships in the ST look so similar to the ones in the OT, worn in and everything? The real reason is that the production design team was inspired by the space ship designs of the pulp magazines. That’s a cool homage but it doesn’t feel like “Star Wars.”