But also, 'Not necessary' doesn't mean 'not worth subsidizing'.
If you think the government finds value in having a connected population with easy access to information then there's value in subsidizing that. Assume the government valued it at $10 a month per person due to increased economic activity made possible from the information flowing, if the market price for it was $60 a month then you have expanded access to anyone who valued it at at least $50 a month.
You can make the same argument for air travel by the way. Why does the government value consumers flying around the country? Why would the government want to encourage people to fly from Charlotte to Florida to go to disney instead of drive to Pidgeon Forge and go to Dollywood? Or fly to NY 3x a year to see grandma for a weekend instead of drive to NY and see grandma for a whole week 1x a year?