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.