The history of the street parade
Launch library · evergreen read

Street parades grew from a genuinely practical need to move a celebration or announcement through a whole town rather than confining it to a single fixed location, allowing far more residents to witness and participate in an event without needing to travel to any one specific gathering point themselves.
This mobile format shaped the whole style of parades considerably, favouring bold, visible spectacle such as costume, music and colour that could be appreciated clearly from a distance by a crowd lining both sides of a street, rather than more subtle performance suited to a seated, attentive audience.
Modern parades, from civic celebrations to community festivals, still follow this same basic logic even where the specific occasion being marked has changed considerably over time. Moving the event to the people, rather than asking people to come to a single fixed venue, remains the whole point of a parade. This is one of those quiet details that separates a genuinely well run event from a merely adequate one.