Hello, let me tell you other advantages of POS over POW.
Since there’s no mining, expensive special-purpose hardware isn’t needed, besides the energy requirements are lower; It’s easy to identify validators with high loyalty, simply pick the ones who have staked a higher number of crypto tokens and a longer duration.
A blockchain that implements sharding identifies stakers in each shard, who take the transaction validation responsibility. Since transaction validation is being done by loyal stakers, security of the blockchain is still very high. Hope that helps!