In those days, having in-house competence to do the coding was very rare. With each step being much more connected to a specific area of competence. Hollywoods image of programmers was that they must not be seen anywhere near a customer.
This led to silos, where design was done by one group of people in the company, then sent to a third party contractor for a fixed scope and price.
This naturally creates a waterfall and when everybody just sees their own silo from inside, nobody questioned the big picture, nor that their own design would be flawed from the beginning. Until the product came back, not at all working as desired.
The biggest improvement today is that teams have much higher autonomy within their fully vertically integrated responsibilities. With wider areas of competence covered within a single team, or even a single person. As such, iterating and focusing on what is most important become more natural.
This led to silos, where design was done by one group of people in the company, then sent to a third party contractor for a fixed scope and price.
This naturally creates a waterfall and when everybody just sees their own silo from inside, nobody questioned the big picture, nor that their own design would be flawed from the beginning. Until the product came back, not at all working as desired.
The biggest improvement today is that teams have much higher autonomy within their fully vertically integrated responsibilities. With wider areas of competence covered within a single team, or even a single person. As such, iterating and focusing on what is most important become more natural.