In practice that's not true on many levels. Law enforcement happens across borders. (extradition (yes, in most cases it has to be a valid crime on both sides)) One country's law enforcement also can influence what other countries do without a good proof of anything. (Kim dot com?) That applies outside of LE as well. (points in the general direction of Middle East)
And then there's the soft influence of "we're big enough, we can dictate the rules, because who else will you trade with" which affected things like patent laws and trademarks around the world. It's interesting to see the US finding itself on the other side of that conversation sometimes.
strictnein's comment was blanket statement, and not limited to GDPR.
More specifically, tuke pointed out the territorial scope of GDPR, and strictnein's response seemed to argue that the underlying premise should be invalid.
My comment was to point to a counter-example that is already widely supported.
And then there's the soft influence of "we're big enough, we can dictate the rules, because who else will you trade with" which affected things like patent laws and trademarks around the world. It's interesting to see the US finding itself on the other side of that conversation sometimes.