Maybe this isn’t right, but I remember reading that most young boys 50 years ago dreamed about becoming astronomers, scientists, firefighters and policemen. Now young boys dream about becoming influencers, streamers, and rich personalities. Was Idiocracy written by a time-traveller? Are we working hard to make it a reality?
But OP asked about “decades ago”. What if humanity was actually making progress in the 20th century, becoming better, and now we’re backsliding to where we were during gladiator times?
More of a cycle, I would argue. Part of the rise and fall of empires or whatever.