I think this is more of a version of the "why have we stopped making good music/movies, almost everything today is garbage?" issue. With the benefit of hindsight, we only remember the greats (and the very worst villains) from past eras. While if we look around today, we see all the people who will never make it into the history books, just like we see all the songs and movies that will never become "classics." Edit:…
I think this is largely because modern geniuses don't market themselves well. I mean the world is undeniably rampant with genius, but if you can't market your genius via social media or other means, then you fade into the background.
Consider that there are people on the spectrum who are bad at social interaction and can't be a 'Youtuber' or 'influencer' so easily.