First link references
https://cacm.acm.org/magazines/2018/7/229033-majority-is-not-enough/fulltext
For their assertion that bitcoin mining pools can undermine the network, but I'm not going to spend one cent let alone 8 thousand to see exactly what the "greedy" miners can do to undermine the network, so I'll cautiously point out that the 51% attacks have been possible for years and we still have no proof of any of that happening on bitcoin. Even if it's a possibility, it's in the realm of counter to the incentive of mining/securing the network, and if it does happen it likely will be reversed, new rules put in place and things will ge back to working in no time.
As for the other article, it's complete horseshit. As Vitalik said, has there been any such attacks on POS.
No
And that's 3 years later and still nothing to show for it.
Let's suppose for a moment that there's ANY merit to this:
If there is a single stakeholder which MAY define all witnesses and then almost do whatever he wants with the chain. Then this is a major risk for the security of the chain. And thus it is not very well decentralized. I don't know what it so difficult to understand with this.
Imagine, someone from another Blockchain doing this to bring down Steem to value his own Blockchain or Steem fork. At the moment this would be even "relatively cheap".
So theoretically, because of the size of someone's stake, they "can" do whatever they want with the chain, saying essentially that with their stake alone, they could force everyone else to comply. Well, good luck getting them to undermine their position so that your unfounded fears and concerns will be assuaged, because in reality, not only is it a complete fantasy to think that one stakeholder could do such things, but it undermines the entire reason for holding stake to penalize, to tax, and to otherwise undermine the power of the stake in relation to how much it is, thereby making holding a certain ammount of stake a risk without any reward, and exactly like a pool of miners colluding to cheat a few bitcoin while essentially destroying the value of bitcoin it's the same for one large stakeholder to invest into the system only to undermine it, because sinking one ship in your head will raise the level of the ocean.
Following that logic, Facebook is not centralized either. There is one shareholder who has mayor stake in the company and which pretty much acts in "the best interest" of the company because of that. So, why do we need cryptocurrencies. Can't we just trust Paypal and Facebook? They are acting in the best interest of their companies too. They're kind decentralized as well. Got a lot of people from all over the world holding their stocks. Let's let Paypal put their money on the blockchain and let them handle the permissioned ledger and it's going to be alright.
The reason I'm in blockchain is exactly to not have this situation. On Steem there was recently a situation where some Witnesses thought about forking the chain, and Steemit Inc said they could elect just the 20 witnesses themselves in that moment.
There is the possibility of that happening, and they said they would do that. Is that decentralization or does it just kinda seem like it.
And of course, as long as they got 30 votes to cast, they could just do that, with 10 votes, especially on the short term, that is much more difficult.
I'm not saying that huge stake holders shouldn't be able to have a big influence. And I'm not denying that this makes sense in the context of game theory. Nonetheless, on Steem this influence is essentially to big, which is a big risk for the chain. So reducing this to 10 votes, would improve the situation while still maintaining the central elements of PoS. (And no, I don't want 1 vote, I want 10).