Above the floor cleaning....
is of two varieties. There is the on-the-fly quick catching of the stray bit of popcorn, or cobweb, and there is the thorough vacuuming of lampshades, upholstery, bookshelves. On-board attachments are geared toward the first kind of use. The second is more easily and thoroughly achieved with a separate canister, or an extension hose (fixed length, non-stretch) and more complete tool kit.
No one has yet created a full, complete set of on-board tools with sufficient length to eliminate the need for additional hose/wands. A longer hose adds weight, and increases the length of the dirt path, as well as increasing the number of bends and turns. More tools equal more weight because of the tools themselves, plus the molded cavities to hold them. Power nozzle canisters offer some benefits, but have a longer dirt path. The hose is heavier due to the concealed wires. Even these units can offer greater utility and user friendliness with a longer, lighter hose that connects to the electric hose for extensive more thorough above-the-floor cleaning,