Built in vacs are great, especially for allergy or asthma sufferers because they suck up dust mites, dust etc. and blow the “exhaust” outside the house. Regular cannister vacuums just recycle the dust into the same rooms.
A central system exhausts outside the house envelope such as into to main motor unit in the garage, basement or through an exhaust pipe through the side of the house. All dust and allergens are gathered and carried in a closed and sealed-pipe system to avoid any re-circulation of dust. They are also very quiet with the motor unit in the basement or garage.
I have a central vac system with some nice options that make it easy to love. I love the quiet and the convenience enough to overcome the inconvenience of the longer (and lightweight) hose of the central unit. These central vacuum systems can be HEPA and high efficient for removing dust and allergens from inside a house.