Corporations is controlled by those who own the shares. 1 share 1 vote. But usually only a very very few individuals own majority of the shares. So they have all power what a "too big too fail corporation" can do.

With Ethereum PoS. It is dependent on ETH being distributed to many individuals. If only a few individuals own most of the ETH, then they will then have the power dictate what is the "truth" in the blockchain. Right now, ETH is very well distributed around the whole planet.

As you can see, one is oligarchic, the other is very democratic.

Ethereum is not a Corporation that is designed to make profits. It is non-profit, it's not even a company, it's simply a protocol implemented in Free Software.