The Great Male Unification is a pretty interesting topic about how men gave up fashion.

Coined by British psychologist John Flügel in 1930, it is considered a major turning point in the history of clothing where the male style stopped being as ornate and detailed.[2] Flügel asserted that men "abandoned their claim to be considered beautiful" and "henceforth aimed at being only useful".[3] The Great Renunciation encouraged the establishment of the suit's monopoly on male dress codes at the beginning of the 19th century.