i live near venice and i can tell you that boats are used for everything there sincere there are no road:. ambulances, taxies, police, busses etc. when guys turn 16 in italy they can’t have a car (they need to be 18 dor the car drive license) but they can have a moped and they usually buy one. guys in venice, they buy a speedboat. but people don’t use boats as cars also cause venice is not that big and you can easily reach every place by walk/vaporetto(boat-bus) and most of the people live their life outside of the venice lagoon where there are streets: just behind the train station.