Companies don't spend their own money. The people who work for a company spend their investors' money, and their interests are only partially aligned.

People spending company money are sometimes far less thrifty than either people spending their own money or government employees, so I don't think you can rank them based on thriftiness. Nor do established companies necessarily provide better service than government organizations. These things depend more on the particular organization's culture and governance, not on whether it's a business or a government.