Has Er Gen's writing style changed in quality for the worse?

1) Immortality is not the issue. The long time spans however, are. The former does not force the later.
2) Multiple worlds do not matter. The problem is the excessive power scaling while keeping the stakes the same.
3) Survival of the fittest would mean something if anything but cultivation had its niche. But it doesn't. If you throw mountains while your enemy is still using a sword to cut boulders you just win, no matter how smart he is. Resource management doesn't matter. Because these treassures are oh so rare and the economy is functionally broken. Which means luck is everything. Or plot armour.
4) Fast growth is only a problem due to retarded power scalings and the absolute status of cultivation. The plebs don't matter if the kings have the power to solo any given amount of them WHILE doing all their jobs better. 

Good stories can attract many readers, not the stories that minority of you like and keep comment and try to represent the majority who don't even care about comment in here 

Wkwkkwwkkw I don't need your permission to insult, same with you guys insult one of my favourite novel without anyone permission.

I don't even care if nobody like you made me in your ignore list wkwkwkwk
Hypocrite? So be it

I don't care !

At least I cannot just let you guys insult one of my favourite novel.

You guys cannot reach the Apex, I don't care what ants like you guys opinion on me.

Okay, time to go ... Good luck guys wkwkkwwkk 

After this discussion i returned to read pursuit of the truth with a fresh mind I have to say, I am really digging it so far, it is much much better than AWE and RI so far. It actually feels like a mystery novel set in a xianxia for once. ( Ch 650 ish) 

I do not agree, I hate any kind of lingering mystery for no good reason. By the way, I read a lot more than 50 novels, a lot more. 

Basically this. I know quite a few people who have completed all Er Gens completed works (including me), and they LITERALLY ALL agree that Pursuit of the Truth was the best of his works, while AWE is the worst. Ironically, ratings are opposite on NU. This just show that people are to used to reading trash. Lets be honest, 99,9% of time when people ask about novels, questions are "is this a harem? or Is MC oped?". The only reason why AWE appears to be good, is because similar novels are all trash.

So, did the quality of his works decrease? Short answer, yes. How? They became a cliche. I won't bother to explain what was so good about RI or PoT. Those who read will understand without explanation and it won't do any good who haven't. Then there comes ISSTH. While some concepts in it were good, but you can also notice the beginning of the decline. If you have read all first 3 of his novels, then you can notice that some arcs in ISSTH feel way to familiar. The reason is that they are practically the re-written version of some arcs from his own previous novels. For example, 9th hex arc is basically a combination of 3 arcs in RI. Er Gen also began to pull out completely random stunts in important parts of the novel with 0 foreshadowing until those arcs themselves. And then comes AWE... It was literally a cliche. The IQ of characters was reduced to 0, hard work and comprehension was replaced with a standard lucky moron MC, any forms of plot or character growth were replaced by the same joke which was repeated over and over again, and the Er Gen's unique journey+doa comprehension thing was replaced MC finding endgame stuff in the beginner village cliche....

Ps. I see comments here complaining about cultivation as a genre and similar stuff. It makes me wonder what are you doing on NU in the first place.... 

Smart has nothing to do with the quantity of your abilities. It is how you (ab-)use them. And: Nothing is overpowered if it has equals. 

Yes it doesn't cover every point you did bring out but a few are solved in CCG by the author simply taking a different aproach and point of view to the problem instead of wallowing in the same usual cliches over and over again at each arc or realm. It's not a question of being the norm or having better writing quality but just going the extra mile and putting some effort to avoid the swamp of templates instead of lazily copypasting stuff, just changing the names.

And for the exemple of LotR, Tolkien mixed power levels quite well in his story by making the hobbit group acting on a different way than the other powerhouses of the fellowship, so it proves that it quite doable to work on multiple angles for power level instead of just fast leveling repeatedly only one character, sweeping all looses end and other characters under the carpet at each power creep jump.