By some measures, Captain Marvel was the best selling character of the Golden Age. His adventures (like this one from 1949) were always whimsical, clever and well-drawn. There was something about the character that lent itself to a light and cartoony touch. Perhaps it was his innocence (he seemed, if anything, less worldly than his young alter ego).
When this artist (Kurt Schaffenberger) became the artist for DC's Lois Lane story he was arguably my least favorite artist with a major publisher; here he's just about perfect.