I'm honestly surprised that the US doesn't have a legal framework to force ISPs to block IPs / DNS hostnames. I've been expecting that for 10+ years now, but it hasn't happened.
In general they're not going to bother with IP blocking; once they've killed DNS, they're satisfied that most people will not be able to access it.
And for the most part, that's good enough. There's perhaps an argument that the US gov't should be blocking IPs/DNS of things like hacking rings and malware distributors that are hosted elsewhere, on TLDs out of their reach (where ISP blocking would probably be the only or at least best way), but they mainly only care about e.g. sites that threaten the copyright cartels, when it comes to legal takedowns, anyway. And for sites that host illegal content, they seem happy only prosecuting US residents who access them.
Nobody has to worry about breaking Thai laws around defaming the King because Thailand isn’t a superpower with the ability to enforce its will beyond its borders.
Everyone has to be worried about breaking US law.
Not every country has this, so no, not "everyone has to be worried about breaking US law".
Regarding Thailand specifically, they have a principle of "double criminality", so people are only extraditable if what they're accused of is a crime both in Thailand and the country they're being extradited to. So maybe not the best example.
Besides, other countries have extradition treaties with other countries than the US too, even non-super power ones.