What Makes Theater Special?

What makes theater stand out from all of the other art forms?

What attracts us to theater to make us directors, playwrights, critics?

What makes it different from a band playing a gig in a small venue, an opera at the Met, a painting, a ballet?

Do our own personal tastes effect our preference of art?

Is theater an equal art?

It seems like a deceptively simple question at first, but there has to be even a vague reason that draws us to theater and makes us stay with it.