We’d go outside? Derive pleasure from being around people near us instead of seeking external validation and watching shows crafted by Hollywood midwits? Maybe we’d have more hobbies and do sports?
Art isn’t keeping you inside, actually technology has made our lives more comfortable indoors, not that it’s always a bad thing. A world without art would be an industrial world where things only have utility and what the look like does not matter. Think everything being painted the same drab color because it’s efficient and cheap. Buildings having the same architecture, think people wearing the same clothes, same colors even because who would care about esthetics?