Frames were quite useful at times, though, particularly for sites that acted as a directory of other sites. With how slow dialup could be it was sometimes nice to have the list of sites you might want to visit in a compact list frame to the left so you didn’t have to hit back 5 times to get back to the directory or juggle multiple windows (because tabs didn’t yet exist).
Frames were a great way to keep around nav before the sticky css attribute. However, they were horrible for linking.