It isn't them though - it is a far narrower group. All blockchains have a rich get richer problem - the earlier you are, the cheaper it is to amass an unassailable position.
Even in something more difficult to collude/setup like BTC, 4 pools could execute a 51% attack. As of Q2 2020, 65.08% of hash power was in China.
It doesn't take many people, especially because you need both money and a desire to be in Ethereum. As another example, 2241 individual wallets hold 42% of all BTC, while 35,604,096 wallets hold 1.24% of BTC - I would expect concentration to happen even more quickly in PoS.
So if all it takes is 4 miners to pull together - and that's never happened - but it would take 70k individuals with Proof of Stake - wouldn't that make it much less likely to happen???
That's only in a fully deployed system. 70k people won't participate in the first buy of PoS ETH - you'll have a far smaller number, likely less that BTC at scale.
Also, ETH has already forked over a doctrinal issue - I don't doubt it could happen again, but the PoS leaders will just directly double down.
This isn't a PoS/PoW argument - more that most public blockchains are inherently winner take all systems.
Even in something more difficult to collude/setup like BTC, 4 pools could execute a 51% attack. As of Q2 2020, 65.08% of hash power was in China.
It doesn't take many people, especially because you need both money and a desire to be in Ethereum. As another example, 2241 individual wallets hold 42% of all BTC, while 35,604,096 wallets hold 1.24% of BTC - I would expect concentration to happen even more quickly in PoS.