The impression I've gotten is that
nobody cares about House of the Dragon due to the ending of the main show, not just the media or any other singular group. Most of my friends had at least some passing interest in GoT when it was at the height of its popularity last decade, but since the ending their interest in the IP has completely cratered. Doesn't matter if they were super invested or just casual watchers, the kind of people who theorized over minute details online or just tuned in for each episode once a week and then talked about it the day after, book-readers or show-only fans; none of them liked the ending and they pretty much all moved on to other things quite quickly. The ones I've brought HOTD up to didn't even know the show is about to start airing and expressed at best a lukewarm 'hmm OK, maybe I'll give it a watch if the reviews are good' sentiment, at worst they've told me that they've sworn GoT stuff off for good after S8.
I haven't seen much buzz about it online either. Outside of dedicated ASOIAF/GoT spaces, almost nobody talks about it even on gaming forums hosting Total War or CK2 ASOIAF mods as far as I can tell, unless it's to post the occasional meme about how much the ending blows or how LOTR is better. It really does feel like GoT's cultural influence died overnight after that disastrous last season.
Speaking of LOTR's superiority, I found a video with a take on why its popularity is longer-lasting than ASOIAF's which I haven't seen elsewhere. I didn't think about it this way before but this does make sense now that I am thinking about it - GoT's shock value really was both its biggest asset and its biggest weakness in the long run, and the shallowness of all its edge & lack of a universally popular message everyone can appreciate (not in a skin-deep token 'diversity & representation' way as HOTD's going for with its literally black Blacks but in the profound and truly universal way that Americans or Western Europeans, Chinese, Nigerians and Arabs can all comprehend the restoration of a rightful king or the revival of traditions and go 'yeah that's cool') have further contributed to its slippage into the dustbin of entertainment history. Said edginess and its conception as a sort of anti-Tolkien 'realistic deconstruction' does also really date it as a product of the late '80s/'90s to mid-2010s when dark grim/pseudo-gothic edgelord shit was taking off everywhere from comics to movies, as well. That people have been increasingly poking holes in its purported 'realism' since even before the show finished airing is just the icing on the crap cake.