Originally posted by From1980 .We addressed this issue very frequently when I worked in a camera store more than 30 years ago. There was definitely a noticeable and measureable difference between most primes and most zooms then. However either type could be equally as good depending what type of photo was needed and what the output would be used for. Lots of casual snapshooters were never going to demand any more from their optics than simple lighting and small prints from color negative film. Most of our customers were well served by using the type of kit zoom that was becoming common then. For the people doing more serious amateur or professional photograpy and expecting bigger enlargements or slide projection the comparison was not rhetoric.
By the 1980's the high end zooms had caught up with the high end primes, by the 1990's they were virtually the same. Now days you can not tell the difference. It is unfortunate that unscrupulous camera stores feel the need to insist people need to buy numerous expensive primes rather than a few professional level zooms. When you sell a photograph no one cares what lens you took it with.