The answer of course is that we still have theatre for the same reason the advent of the novel didn’t kill the play, and the advent of film didn’t kill both: because humans love to share stories, and each new way of doing that gives us more opportunities for, respectively, escapism from and better understanding of the world around us. Reading novels about people different from us engenders empathy and watching sad films boosts feelings of group bonding: theatre has an added feeling of liveness and shared experience – like a cross between a gig and the cinema.
Sometimes you want to experience art on your own in the bath, and sometimes you want to share that experience with a bunch of strangers in the dark. We live in a busy, complicated world – there’s every chance you’re reading this on public transport, or on your lunchbreak, or in a few snatched minutes away from your emails – and it’s hard to carve time out to interact with most art forms without checking your phone occasionally, or “double screening”. Doing several things at once makes us less efficient at all of them, and is bad for our brains – but theatre demands your complete attention. (Not least because if you do get caught using your phone, Kevin Spacey might shout at you.)
(via)