I don't want to say there are no such trends, but there is significant bias that lends to their appearance.
I remember as a kid growing up in the 80s looking back to the ridiculous fashions of the 60s and 70s and thinking "People eventually see dumb fads for what they are, thank god we wear reasonable clothes now". Most adults grow out of that and come to the realization that all fashion is arbitrary, but we preserve a similar sort of blinders for issues around morality.
If you live in the present, as we all do, then statistically, you're likely to agree with popular ideas of the time and disagree with ideas of the past which are different. Since ideas change in increments, this will always look like progress.
And even if the arc of time does bend towards truth and goodness, there are certainly sidesteps and backslides. How dire do that have to be that we can't shrug our shoulders and say "we're basically headed in the right direction" 50 years ago, Iran was a lot closer to the western world in terms of gender equality and freedom of expression. Now young women can get pulled into a van and beaten for wearing lipstick. And it doesn't look like that's changing soon. So that's a backslide that's lasted a lifetime and doesn't seem to be going away. I'm not saying that censorship specifically would have avoided the supremacy of those bad ideas, but it's at least an example of bad ideas bending against the supposed forward march towards truth and justice in a way that has lasted half a century and will continue.