I completely agree that a lack of manual curation is a problem. However consistanly good content creators do get noticed.
Maybe a lot of poor quality content creators who used bid bots to inflate their post values were also inflating their egos. In reality their content wasn't that good. Steem isn't here to reward people based on effort or those who make the most noise.
Find me some high quality content that isn't rewarded and I'll upvote it. It's difficult to find this. I can find a lot of crap that is over rewarded, but less and less.
Next we can deal with auto curation. However, it's a little harder to punish people for voting without punishing the content creator because everyone will just make alts for curation.
As for double posting. At least block trades downvoted it removing the rewards for those people who now wasted their votes. At worst, I've seen people self vote it. Actually, the best I saw was someone who had an emergency post saved for when it happened. Unfortunately, you cannot set beneficiaries or decline rewards after you post. It would need a hardfork to change this and it is a minor issue.
Just like costanza wrote, we are slowly killing off minnows and low level dolphins and that is slowly reflecting in the price of steem.
Relative to BTC the price and rank of Steem has increased since HF21 was implemented. This means the downvoting hasn't destroyed the price.
Admittingly, there was a decline in the value of Steem before the hardfork. This could have been whales and orcas running away. But statistics show the amount of whales and orcas and dolphins has actually increased and so have over all active accounts.
The decrease was probably related to people who foresaw the demise of bots (ie. the people only here to delegate to bots). Therefore, I think the price decrease was also a result of Steem doing an update that investors didn't want (EIP instead of SMTs), let's wait for SMTs.
This is actually the primary way people actually got noticed in the early steem days. Most of these people were able to build communities around themselves and those are the bigger dolphins and whales we have today.
The other way is to join a wave. I hated the EIP and agreed with proposal project and that set me apart from the wave. I could not be speaking up about the things I find wrong and that would reflect positively on my author rewards but that is not in personality. Just speak against bots and see how quickly ocd discover your posts.
I would love to see the stats on new accounts, active minnow accounts, power downs and power ups. That tells you more about the overall health of the blockchain ecosystem. I am sure you are aware Steem Inc stopped selling their Steem for a short period of time and that stabilized the coin in a torrid bear market.
But if people are no longer engaging as much as they used to pre-hardfork especially on lower level accounts that account for the largest group of individuals just tells you everything you need to know. Would you know where I can get such stats because I could do a deep dive and come up with a post. Right now I am going off more of my experience rather than irrefutable stats.
I was against the use of a non-linear reward curve. I would be more in favor of a step. Reducing rewards for people who earn under 2 Steem would have been more appropriate than 20 just to get rid of the people who are voting at 0.1% with only 20sp in their account or whatever.
I don't understand people used to get rewards by all sorts of ways. However, Steem has matured. Just think of the wild west analogy.
There are a lot of statistics out there for Steem. None of them I've seen are showing bad new as a result of the new Steem changes.
I follow abh12345's engagement league, the engagement seems stable. No one really cares that comment voting is no longer as common. Honestly, I think the decline in Steem's price stopped it just as much as anything. People will engage if the content is interesting or 'engaging' that's about it.