There’s a fundamental difference between most private entities and public entities: the profit motive, which is the reason why private companies’ interests are misaligned with the interests of the people they’re meant to serve in a lot of cases.
The search for profit is the source of a lot of waste of resources that would be better used providing actual services (eg. Marketing for a fire station makes zero sense).
Of course, this applies to entities that provide services and not those that build your phones.