It's not so much that the government knows better, as that they have different priorities and the power to mandate that those priorities are respected.
The priority of cell phone manufacturers is to make money. When they can only obtain this money from their customers when their customers freely decide to give it to them, their priority must be to make products that their customers will buy. This is how the cell phone manufacturers are serving the demands of their customers.
I wonder- what priority of government are you referring to that is different than serving the demands of the public?
Understanding is always the understanding of a smaller problem in relation to a bigger problem. -- P.D. Ouspensky