Calling cinema a "new form" of theatre is quite a simplification. It was certainly inspired by theatre, but the two differ in almost every aspect: medium, communication language, cultural role, and audience dynamics. Most people throughout history probably never experienced theatre or opera – so they didn’t move from them to cinema; rather, cinema emerged as a more accessible and reproducible medium
for those.
Theatre and opera are regarded as high art because they are performed live in front of an audience every time, demanding presence, skill, and immediacy – unlike cinema, which relies on a recorded and edited performance.
