"Leaping tall buildings in single bounds" and being "faster than speeding bullets" are feats of strength and speed that may have seemed impressive in 1938 when Action Comics first hit the stands. However, as comic book stories grew larger and larger, so did the acts of heroism. As a result, Superman had to perform even greater feats to keep up.
Source:https://www.cbr.com/superman-strongest-feats-comics-ranked/