They work very well
"Banning blowers will mean less jobs," argued one landscaper.
"Not exactly if you have to hire two rakers to take its place," someone responded."
Studies actually show that it make take only 10-15% longer to rake with the same manpower. Source: ZAP
When thinking of 'cost' one has to compute the external social and enviromental costs (noise, pollution) into the equation.
So which is cheaper? Two men with a rake or two men with a blower or broom?
The Japanese invented the 'blower' but brooms still seem to work.
Photo by Jonas B.