Sure, but if the majority of validators are actually run by the project owners it's effectively centralised. And it's easy to maintain this control if you have the majority of coins to stake. It's not Sybil resistant for this reason - all validators could be owned by one person and you would have no way of knowing.

>all validators could be owned by one person and you would have no way of knowing.

all bitcoin miners could be owned by one person and you would have no way of knowing....

>it's effectively centralised

so your argument is not that it is not possible to have security AND decentralisation with POS, but that it currently is not the case, right?

> all bitcoin miners could be owned by one person and you would have no way of knowing....

Sure, it's entirely possible that BTC is also centralised and controlled by wales. I was merely suggesting that the reason PoS systems haven't been hacked (much) yet is because the validators are controlled by project owners, so they are really centralised payment systems in disguise.

There's a difference though: buying initial stake in PoS may be similar to buying an ASIC in PoW, but mining a chain has a real cost (electricity) in PoW. In PoS there's no cost to mining, so validators have an incentive to stake all possible forks. There's no way to have consensus on the correct chain, because real resources haven't gone into building one up.