No, it’s not. From the POV of the patron, theater is not life and life is not theater. It’s a lot more like TV. The stage is a box where human beings are speaking lines and doing things, but for all the effect they can have on your real life, you might as well be watching a TV set. You’ll go home after the play and maybe think about what you’ve seen and heard, but the same could be said of the experience of going to a theater to watch a movie.
Real life is when your boss fires you or you get a raise, or you are involved in an auto accident, or you help a friend who’s got a problem. The stakes are real and the consequences affect you personally. It’s nothing like watching a play. Or a TV show.
It’s real life in the sense that those people could screw up and it would be real, not edited out, etc. You’re watching those people’s lives. It’s just like if someone came and watched you get into your auto accident or watched your boss fire you. You’re watching them do what they do.
I was injured onstage once to the point where I had blood running off my leg. I didn’t react to it when it happened and hopefully not many people noticed (my exit was shortly afterward, but did require me to leap from the stage into the aisles and go running all the way to the back of the seating area and out that door…) but when you watch a play, you are definitely seeing real life, with all of its accompanying risks.
Real life doesn’t just have to affect you. Seeing an accident is just as real as being in one.
The big difference between theater and TV (or film) is that on TV you get to see only what the director wants you to see, while on stage you get to choose. On TV what you see is an artificial environment, which you get tricked into believing, while on stage you must choose to believe. Read the beginning of Henry V for a statement of this.
Plus the camera distorts. I was astounded to find out that Mission Control in Houston was a lot smaller than it looks on TV.