Not sure why you are downvoted. Some countries even use them during testing times so students don't cheat or get distracted or whatever when taking tests. I'm not even kidding
Back when that bill I linked was introduced, the generally-accepted narriative was that "sure most governments can shut off the internet to their own countries, but the U.S. can shut off the internet for the whole world." So, yes, other countries have internet kill switches, but if that's (still) true, probably no country can more drastically hobble the worldwide internet as a whole.
The root DNS servers are in the U.S.. The first internet backbone is in the U.S.. In 2010, it seemed like the U.S. government did have the power to make virtually the entire internet grind to a rapid halt.
IIRC there was also language in the bill saying all kinds of bullshit things about how since the internet was started in the U.S. by a U.S. government agency, the U.S. "owned" the internet and thus... had every right to shut off the internet if they so chose or some shit.
Since I first saw your comment, I did a little googling. Not a ton, and the sources I've found so far aren't all that reliable. But mostly the answers I've found say that the U.S.' ability to shut down the internet to other parts of the world is more limited than I'd heard it was in 2010. I'm not sure if it was overstated back then or if things have changed since then (or if the sources I found are wrong and the U.S. government could pretty much destroy the whole internet if it chose to.) But hopefully it's true that the U.S. doesn't have that kind of power.
And you don't even need them, for the short term. Virtually all of your DNS queries are answered by machines much closer to you than the root servers. If you don't have it in a local DNS cache, you go to the authoritative nameserver for the domain you're requesting, which is also not a root DNS server, but one of the millions of other zone nameservers. Shutting down the root servers can also be routed around by setting up a different configuration, or just routing the addresses for the roots to something else that you control.
Then you get to the backbones, which are a bigger deal. Shut a few of those down--maybe with the enforcement help of local cops and the FBI, assuming you can get them on board--and you'll slow traffic to a crawl. No Netflix for most folks, not for a while. But communication itself would still find a way around.
And all of that assumes he can even get anyone to agree to this, and he's probably the only person with any power who's stupid enough to think this is a good idea. It just doesn't work, not on any level, not even if he takes office, still thinks this is a good idea (which he doesn't, this is an obvious bluff), and can find a bunch of idiots in power willing to help.