For the record, I'm somewhere around 25 episodes into the donghua. I don't know anything about the webnovel; this post is about the donghua.
First off, the writing is weird. The beginning was ok, Han Li gets put in classic main character situations and does main character stuff. It was predictable but enough to get me a little hooked. It however continues being predictable later on and the story is simply linear and uninteresting - often boring. This isn't even the biggest problem - which is the straight up weird and problematic stuff like after Han Li saves her from being raped Chen sexually assaults him??? Hello??? Worst of all, why isn't this painted as a horrible thing to do??? (Fine, I'm exaggerating my own surprise, but that's only because I'm desensitised to Chinese shows doing this by now.) Also when him and that woman (forget her name) are trapped with the monster which they manage to defeat together which magically coerces them - both shown to be unwilling and only into it because of the magic - into having sex??? YES I'VE SEEN THIS STUFF BEFORE TOO BUT IT DOESN'T GET ANY LESS MESSED UP EACH TIME IT HAPPENS! These might be the worst cases but there's also lowkey ableist subtext, hugs without asking consent... the list goes on, and I'm not even far through this donghua.
Not only is the story boring - the characters are too. Characters other than Han Li don't get much of personalities or development, and the few character traits they are shown to have are vague and shallow. They rarely get scenes just by themselves, and when they do, it's not because it's necessary or expected for the plot, or it's used very simply to show their very vague and shallow (and often singular) character trait. There's lots of characters but each only gets their little bit of screentime when Han Li is around - partially due to the linear structure of the story. In particular, the female characters feel poorly written - there aren't that many of them but in addition to my previous complaints about characters in general, they either have no personality or an unrealistic one, they don't have agency and constantly require saving by Han Li (not to mention I think it's clear enought that this is turning out to be a harem donghua, which I just dislike).
Han Li himself is also boring. He has strengths - such as his gardening skills, quick wits and generic carefulness. He's shown to be humble, and also shown to be uninterested in anything romantic or sexual - this is often shown as a positive trait in Chinese media, particularly the latter (which is weird in its own right but I'm not getting into that now... headcanon they're all aspec though). Han Li isn't shown to have any weaknesses, and while he isn't amazing at everything, he's shown to have a large variety of strengths and ultimately he feels very much like a Mary Sue. He doesn't have a personality and everything revolves around him trying to get stronger. He does a lot of helping of other people along the way, making him a moral and agreeable character without any other outstanding traits. He doesn't have particularly strong emotional attachments to anyone, which is fair because it's the natural result of his characterisation, but with the blandness of everything else he's a very boring character. He's a nice guy who's very clever and wants to get more powerful - and that's it.
The animation is alright, mouth movement and occasionally generic movement feels off though. Plus a lot of faces look really similar and facial expressions aren't great - not even with Han Li. The rest of it is fine but nothing mindblowing. The aesthetics and visual designs don't stand out in any way from any other cultivation setting.
The worldbuilding is simple, a very generic cultivation genre world and magic system, but it means with all the above there's really nothing exciting going on with this show.
The two cardinal sins of this show is that it's boring and problematic, and unfortunately both of those are unforgiveable. Maybe watching an animated show simultaneously with your third watch of Arcane isn't the best idea.