Yes... that is true on an individual level, but that doesn't work across all social strata. An upper class lady in the 1920s may not have been protected from predatory members of the upper class, but she was certainly protected from predatory members of lower classes.

If Lady Blatherington-Forsythe-Smyth has someone to fear, it isn't the butler, the kitchen porter, the stable-hand, the groomsmen or anyone in the economic strata beneath her. It's Lord Blatherington-Forsythe-Smyth and his friends. She has a degree of safety afforded to her that Betsy the scullery maid doesn't have.