Most of the condemned movies were foreign films, not all that accessible in most of the US. The Legion of Decency had its impact on preventing Hollywood from making bad movies in the first place.
There is a lot of nonsense about how the laity had very little influence prior to Vatican II. The reality is that the Legion involved the laity heavily. Not only in terms of rating movies after they were made, but in Hollywood there was a semi organized movement, sometimes called the “Catholic Mafia”.
Actors, directors, producers, and others often declined to participate in movies that went against Judeo Christian values, not only because they feared boycotts at the theater, but because it went against the values of those particular artists.
If anyone had tried to open an abortion clinic before Vatican II, if had been legal, it would have been shut down by the local Catholic laity if people knew about it.
Landlords would refuse to rent, vendors would refuse to supply, there would have been 100 people in front of the doors.
Since Vatican II there is far more talk about the lay apostolate, but far less action by the laity in the real world. We are now in the era when most laity are passive.