Children find inflatable furniture fun, but why would an adult own some? Well, first of all, adults are allowed to have fun too. Second, some people find them more comfortable then regular chairs. There is also the practicality of inflatable furniture. It can be deflated and put away in a closet until needed again. And there is portability: it can be put in a car trunk and inflated once your destination is reached, whether it is a camp site or your new dorm room.
Here is a nice, modern-looking example I like:
Inflatable chair for adults pictured: Intex Recreation Ultra Lounge with Ottoman
Pictured above: 1-Bestway Perdura Air Chair Inflatable Furniture 2-Bestway Moda Inflatable Chair, Blue 3-Aircee (TM) Home Seat Inflatable Sofa Air Chair (Green) 4-Smart Air Beds SUMO000025CW ChestAIRfield Inflatable Chesterfield Chair - White 5-Intex Inflatable Cafe Chaise Lounge Chair and Ottoman, Orange