> There's plenty of sites that operate entirely within the US and it's trivial to hard block everyone else.
It's trivial to block IP addresses listed as being somewhere else. That doesn't block people in other jurisdictions from using a US IP address, either by renting or compromising one in the US or having administrative control over one somewhere else and then setting its metadata to whatever they want.
Well yes but once you're in the US someone owns the machine you're getting hit by and you can make them take it down. People won't just throw their hands up "well the operator isn't in the US nothing can be done", they'll just make DigitalOcean block them.