The Silver Age threw away heroics and heroism, the Bronze Age threw away decency and morality, the Iron Age forged tiny cages for people’s imaginations, and the Clay Age finger painted with their own poo, for there was nothing else to throw away.
Of the "big three" who'd been considered such the last few decades, I have no Clarke remaining, not even Rama, and only a couple Asimov. Lots of Heinlein juveniles though.
Why? Because while Heinlein's characters were often frighteningly competent "men with screwdrivers", they were also often big damn heroes, sometimes hucksters, taking risks, often of the life or death variety, and going into the unknown because it was there.
It is no surprise then that at the recent Geek Gab with Jeffro, Wright, and Razorfist, (I think it was) Wright, in renaming the big three, still included Heinlein. From the writers before that, he included A.E. Van Vogt.
My only exposure to Van Vogt in decades past was the weapon shop stories of Isher, and even there, you could tell there was something special. Perhaps the most blatantly pro-gun, pro self-defense, anti-centralized power message short of some libertarian message fic, but unlike those, poetically written. They stuck with me all of these years.
Besides horrible works with a pervasive sense of wrongness like A is for Anything, this is another reason Damon Knight is owed condemnation.
Update: I've got more coming out on Asimov tomorrow.