In my particular town, we once had a Carnival, started around the 30s it was called the Hospital Day Carnival, and money was collected for the hospitals.
At the birth of the NHS it became a standard Carnival, with decorated floats, Fancy Dress, and Marching Bands, cubs, scouts, guides, brownies etc .
This parade wound it's way through the town and halted on the city park, where a days entertainment took place, sports, dog shows, marching band competition, etc, etc.This carnival was stopped a few years ago because of the cost of policing it.
When the disappointment of losing the carnival had died down, the Caribbeans of the town started one of their own, and then a little while after the Asians started an event called the Asian Games.
Both these events cost more in police resources due to the presence of drugs, knives, rival gangs etc.but are allowed to continue year by year.