that power isn't to compete "over the ledger", but kust for the next block so they can get paid. its a business. it's literally no different than starting a company that makes shoes or builds houses or teaches people in a school. that is simply a business. the difference is that when somebody becomes part of the Bitcoin economy, it doesn't matter how big and powerful any of the miners are, that oerson still has the same value in the Bitcoin economy. big or small miners don't change that value.