There's nothing wrong with PoS as long as it is understood as a mechanism for diffusion of power and trust, like a multisig or a corporation. Probably PoS protocols do not need to have in-protocol slashing. Solana has already thought of this and does not have slashing IIRC.
PoW has its own problems. It is likely to be unstable for various reasons in the absence of inflation. I don't have time to find all the citations but there have been many papers about this subject. It's also not great for the environment, and there is something unfortunate about the fact that the best trustless protocol we can come up with as a species requires massive waste. Maybe it is currently the best we have but trying to come up with reasons that the waste is actually OK is a waste of time IMO.
It just shouldn't try to pretend to be a trustless protocol like PoW. Some of the smarter PoS researchers are already catching on to this: https://dba.mirror.xyz/UTPfxWe65dYrUu_RJX-5VkAJypFRyw3AZh6m0...
PoW has its own problems. It is likely to be unstable for various reasons in the absence of inflation. I don't have time to find all the citations but there have been many papers about this subject. It's also not great for the environment, and there is something unfortunate about the fact that the best trustless protocol we can come up with as a species requires massive waste. Maybe it is currently the best we have but trying to come up with reasons that the waste is actually OK is a waste of time IMO.