There's something of a sweet spot for some of this as well. Too old and it's well appreciated as a progenitor of a trope - Checkov, Shakespeare, Beowulf. There's a chunk of things in the last century that haven't quite reached canonical status in that way, but almost definitely will in the next 50-100 years, so people don't quite realize how influential they are yet.
I've noticed that I myself cannot stand games significantly older than my own coming-of-age era. So anything less than VGA is hard for me to appreciate, despite an interest in learning about such things. Let's Plays and video reviews by more patient and tolerant players is how I appreciate them now.
It almost invented the Fantasy genre as we know it today.
It is still very much appreciated, but I've found that some people think it is boring.
Examples given were the Mona Lisa painting and the yin-yang symbol.
IIRC, I read a bunch of this media criticism (alarmism) stuff during dial-up era (post PC, pre Web). Their warning was that digital reproduction would accelerate the process, up-end our notions of intellectual property, swap all the gatekeepers for a new set of goons, etc.
I'm ambivalent. The more things change, the samer they get.
For my part, I sort of adapted, adopting a pseudo Beginner's Mind viewpoint, to accept and sometimes embrace a creative work both for what is and what it was.
One example.
I try to remain ignorant before viewing art and then back filling the context afterwards. I was totally unimpressed by Rothko. Then got into a (friendly) debate that revealed my puerile closed-mindedness. Then binged on his ideas and works. Now I think he was and remains brilliant.
Also, I don't think the replication banality apocalypse actually happened. Just the opposite. Contemporary music (for one) has never been more exciting to me. Today's artists are creating works my generation only fantasized about.
Sure, Sturgeon's Law is timeless. But today's best works are just as good or better than ever. And we somehow both lowered the barriers to entry and raised the ceiling. (There's probably a bigger lesson in there somewhere.... Hmmm.)
Any way. Thanks for reading this far.
TLDR: Arguments about culture are unending. Just roll with it.
What I'm thinking of is more like records in athletics. It's hard to appreciate how good a sprinter was in 1950 when their world record time wouldn't even qualify for a college track meet these days. Even if you mentally understand how good they were, and how what got them to that level set the groundwork for what's making people so much faster now, it still looks like someone running fairly slowly.
In some ways, it's a sort of artistic Eternal September.
Both Fleming and Le Carre had experienced real-world spycraft, and so their competing visions of fiction both had the pedigree of realism, but applied in different ways and with different worldviews.