There's a clear distinction between evaporating morals in general and the fall of "morals I personally agree with" and I'm pushed to believe that the OP is miffed about the latter. That, or it's the "they don't build them like they used to" effect misattributed to declining morals. If you loved
Dragonball or
Naruto as a kid, watch it again now, and be disappointed in what feelings you get from them compared to how amazing they were to you when you were smol.
But that's an easy answer, and it ignores some very real changes in the face of modern fiction.
I'd say that these changes aren't a result of declining moral standards at all, but an expansion of the moral standards that are being displayed. It's easier than ever to produce a webnovel and we've burned the majority of our gatekeepers at the stake. This means that (just about) any person from every political alignment and worldview can post on places like SH and the art's only getting more and more popular. It's much more likely that an argument that says "this field is devolving into degeneracy" is really saying "this piece of art pushes an idea/contains content I'm uncomfortable with and I don't think it should exist" the latter of which is a valid feeling whether it's right or wrong because it doesn't hide behind some kind of social authority, but if people were to say that, they'd have to present their own personal beliefs in the open without protection from said social authority, and not everyone is ready to be scrutinized by a jury of their peers.
This video is relevant.
This whole thread seems like someone who just discovered people like to write fuck up things for fun. (something that has been going on since... forever). Either a child whose legally now adult able to access theses places and is shooked or an extremely sheltered adult.
People just like to write fucked up things for fun and live their lives in the real world normally.
nothing bigger than than that.
Back then there were fed up web novels and now there are f- up web novels.
I rather that than a nanny state and pearl clutchers. As long as they give warning on thier work so I can avoid topics I dislike, then I dont care.
This is a less elegant interpretation, but one that's none the less solid, and may actually be closer to the truth.