Three points on this speaking as an indie dev/artist of non-erotic games.
1.
There is nothing wrong with using third party assets to make your art. It's HOW you use them that matters, because that will affect people's PERCEPTION of your creative work.
The question of originality and creativity will always arise when devs/artists try to use stock assets either as is, or with very mundane alterations, instead of trying to trying to turn those assets into something more unique.
I've seen other devs be called thieves, and their games get called out as "asset flips" if they so much have the audacity to include a stock CC0 asset like a piece of furniture (even though that is the whole point of such an asset). God save you if you decide to use a highly recognizable stock asset like a full character model, if that model has also been used in another, more popular game.
I don't believe every content creator needs to try to be super original with all of their designs, or try to create everything from scratch. That's just not feasible for most of us, myself included. However, people may not be as understanding when they evaluate your work.
2.
If a certain style or trend becomes popular, people may start to find it boring, or they may start criticizing devs/artists for not being more original.
People tend to dismiss platformer games because there's just so many of that style of game being made every day. Doesn't matter if the dev included some unique, never before seen mechanics. People may trash it just because its popular.
Same thing might be going on with art that uses Daz, HS, etc. It might not matter how unique the artist tries to be with those assets, if people perceive the style itself as being overdone.
3.
It is much harder to achieve uniqueness with character art that uses a 3d, realistic style like Daz. Stylized 2d characters such as those found in anime and comics can really push the boundaries on what can be done with the human anatomy, while still being believable.
That is also why there is a far more degree of originality possible in the anime/comic style. If you try to do the same in Daz you won't be able to get nearly the same results or worse, you will fall deep into the uncanny valley.
So most Daz characters end up looking really samey, which once again affects people's perception that the artists are getting lazy and the style is getting overdone.