It's only cheaper for the consumer when there is a forcing function for price. In a competitive marketplace - lets say breakfast cereal - if you're inefficient another manufacturer can undercut you while maintaining profit margins. There are ways around this of course through product differentiation, but something basic like cornflakes all hover around the same price point. All manufacturers are trying to improve efficiency because they know if they don't their competition will.

Now pick something that's a natural monopoly, like water supply. Consumers can't choose water suppliers - deploying pipes is prohibitively expensive - so there's no incentive to lower prices. Instead the efficiency goes to paying shareholders and management. Additionally these companies often have set leases on the infrastructure. If you have a 20 year contract and you know the pipes will start to fail in 25 years if you don't do maintenance... why do maintenance?

Government departments might not be the most efficient, but we can demand they're open and report what they spend money on.