Theaters and circuses in ancient times were completely different from theaters and circuses today.
In what way were they different and how is that relevant? The point is that we went their houses of entertainment. Whatever that entertainment happened to be. That is the first step to assimilation. First we break bread with them then we follow their ways. Then R”L.
True. But it needs to be pointed out that many of our rabbis do not see movies or theater as asur.
That is true. Many of your rabbis don’t. But that is not the point I was making. A rabbi is qualified to determine such a view. A person who has little knowledge of Torah is not.