The government could trivially shut down the internet.
They could easily raid the ICANN and IANA offices in playa vista and shut down global DNS in about an hour if they wanted. It's just a single floor, you could probably do it with 2 police officers.
The chains that bind them from doing so are those of public accountability.
A diligent public strangles the powers of a revanchist government.
Again I agree with you there are regrettable policies that should be addressed. Governance offers us that mechanism. That's why it's preferable as an institution in deciding public policy.
I'd rather have our imperfect government with their awful War on Drugs running the show than say Beyer, who marketed heroin to kids for mild ailments, or Purdue pharma which peddled opioids, you know, as late as last year, or the huxster Elizabeth Holmes or the price gouging Martin Shkreli or RJ Reynolds or any other profit seeking unaccountable entity.
Replacing the FDA with say a board of Shkreli, Holmes and Purdue? Yeah, I'm sure that'd go just great.