That belief is contra to the concept of an immutable decentralized ledger, which means ETH isn't canonically a cryptocurrency, an immutable ledger, or a decentralized ledger anymore. The upcoming (well, it's never going to happen) POS fork is going to centralize it further among the very small number of massive whales who control the ecosystem.
In PoW only a few people have the resources to build and run mining farms. Certainly not me. In PoS anyone can stake on a desktop or laptop. This greatly increases the amount of people who can participate in the network.
Just to clarify a bit in an edit here -- As a general comment about POS vx POW, you have to purchase a huge amount of the cryptocurrency to participate in POS in a meaningful way -- so there is a cost to that just as there is in mining. The recurring costs of electricity are not there in POS of course.
I'm relatively confident the network will never go POS, but not confident enough to put money on it anyway -- you never know what these kids will pull.