Being on dA for nearly a decade now, it's pretty depressing to see some artists just not improve their craft, or just simply become WORSE than when they first started.
I knew my shit was a WIP and I still think it's a WIP, but it's because I always welcome critiques and open doors to improvement. But there are some people who I follow that are friends I've met through the years, and they barely improve, if at all (probably the only change was they managed to get a scanner and not photograph their drawings for upload).
You should take a look at the "Draw This Again" meme that gets passed around. While there's some great improvements among them, there's some that'll make you wince, especially if the old and new are many years apart. It's like "what the fuck have you been doing all these years?"
I guess I'll wrap this up with a deviant that artistically fell from grace before it could even embrace such a concept. It was another friend I knew since around 2007-2008 that did some... okay art, at least by amateur standards. She was another one of those beginner artists that drew in anime style. The good thing is that that style it's easy to get better at that with enough dedication and experimentation. Sure she was wonky and the eyes and mouth were fucking off, but there was room to improve. And she was getting there, her lines were more refined, the faces looked a little more correct, it was getting there.
And then she opened a Tumblr account. She took on all the worst elements you'd expect of your usual Tumblrina artist. Fat manfaces, giant lips, meth addict eyes, you name it. While she improved on one thing, she fucked up two other things. And when she uploaded artwork to dA, nobody would tell her her art looked bad (probably because we'd get banned for calling out bad art). "Wow this looks great!" "Wow you improved!" No she fucking didn't. It got so bad to the point that I checked off further deviations from her. And the saddest thing about this is that she still draws like this.