I'd have to wonder at the product we'd get if we swapped out Comcast and let the Federal Government take over their business.

I think it would cost net twice as much (total expenditures out of the consumer pocket via taxation, the plans wouldn't cost more), be about as reliable, about as fast, lose lots of money and still be completely unaccountable to its customers. The system / infrastructure upgrades would be slow, bureaucratic, always vastly over-budget, and a constant funding fight in Congress.

(I say this understanding fully that few advocate for a federal system, but rather local muni connectivity)