A hose reel makes a hose easier to use. These big metal or plastic reels, like big spools, let hoses wrap around them and unreel as they spin under control. A hose on a reel can easily move from place to place and unreel your hose to the right length.
Hose reels also make for tidy storage, requiring less space than hoses do tossed haphazardly. For the tidy gardener, a hose on a hose reel just makes more sense.