This is still a common trope, it just shows up in different ways. Again, in the prose Howard often contrasts conan with Civilization, but he is often just talking about cities. Characters going to the big city and loses themselves their because of its corruption of their character is something you see all the time in cinema (it isn't the only way this topic is handled, but it is a concept that is out there).
All that said this is just one aspect of Conan. I don't think you can pinpoint one feature of the stories, declare that feature no longer relevant, and then say therefore what Conan embodies is irrelevant. If you ask 8 different people what Conan embodies you are probably going to get 8 different responses because he can resonate with folks for different reasons. But the proof is in the pudding. The stories are still being published and read (they wouldn't be getting published if people still weren't reading them). Someone has linked to a successful video game. There are still comics. The character still shows up in places. Everyone knows who the character is. Apparently there was even a french movie in 2023 about a female version of Conan, called She is Conann. In recent years they have been trying to get a Conan show off the ground again and the may still well happen. I mean if people don't like Conan, that is fair. I get that a lot of folks in the thread find the character problematic. But that doesn't make Conan a dead property
I don't see much evidence of this trope in recent fiction, cinematic or otherwise. It's not the same thing as conflict between city and small town values (both the city and the small town are civilized)--and frankly, I haven't seen that one too much recently either.
I'm not claiming that the corrupting influence of civilization is the only feature of Conan, but that it is a pretty defining feature, and one of the primary things that you can get from Conan stories that you wouldn't get from other fiction. What I'm positing is that, in the huge marketplace of fictional ideas, if one of your defining traits doesn't resonate widly anymore in the 21st century, then you are unlikely to remain influential when there are so many other fictional ideas to choose from. Of course people will continue to read and make adaptations of Conan--it would take a very long time for such a singular character to completely vanish from culture--but the entire premise of this thread is that he's no longer familiar to a wide range of DnD players, and I think that's almost certainly true. He was once one of the fundamental texts of fantasy fiction, and now he isn't. So I'm speculating about why I think that is.
Oh I think there will always be a frontier somewhere. But if not, we have Conan's experiences with civilization, where it's soft and corrupt, too. I think that may remain an issue as well. And ... the pulps progressed into noir, didn't they?
There are still frontiers. But a lot of genres built around frontiers are drawing from history anyways, not from the present. The west was well over when cowboy movies were at their height. The frontier was useful in those, and in Wuxia, because it is a very good setting for telling certain kinds of stories. I just need to know that frontiers existed in the west or in China for those stories to make sense and have resonance.
I mean manorialism and feudalism are not really that relevant to people playing D&D these days but plenty of fantasy includes trappings from those times
On the contrary--I think we have already reached the point where there are no longer any frontiers, and we are rapidly approaching the point where no one will even be able to recall one. There's still the, you know,
final frontier, but given how space hasn't turned out to be full of aliens after all I think it's unlikely to inspire the same kind of fiction!
Of course the concepts forged in that particular environment won't go away, but they will be warped into whatever shape best serves the narratives that resonate with people in the future. As have concepts that arose from feudalism; hardly any fantasy, including LOTR with its divine right of kings, really tries to portray a feudal world. The exceptions, like Game of Thrones, are often deliberate deconstructions of more traditional fantasy tropes. It's the
flavor of feudalism that we see in fantasy, without its substance. Just like Wolverine has something of the flavor of Conan, embedded in a worldview that is diametrically opposed the one REH was articulating.