Most of the time, the 116-year-old movie theater business is rather humdrum.Tickets get sold. Images get projected onto screens, sometimes in 3-D. Every now and then, change-phobic cinema operators get excited about an innovation. The armrest cup holder, for instance, was patented in 1981.But these are not normal times at movie houses. Just ask Adam Aron.A year ago, Mr. Aron, who runs AMC Entertainment, the world’s largest multiplex chain, was feeling unusually invigorated about his antiquated industry. Even with streaming services proliferating — and attendance in North America declining — cinemas worldwide collected $42.5 billion in 2019, a record high. “We …
