That's a very US-centric view. Twitter has a lot of non-US users as well. In fact, a Dutch right-wing politician was apparently targeted in this attack.[1] How would such a requirement help in this case?
Maybe the Dutch should do the same thing. Or throw their lot in with a country or group of countries they trust (EU, EU+x, NATO, etc.). The geopolitics of this would be complicated. But that has been life for small polities for thousands of years.
You can federate services in ways that allow entities in different countries to control their own user data, while still allowing interactions between users in different countries.
Your private messages with other EU users might be stored only in Europe, with only Europeans able to access it. To the extent you message with people in another country, those controlling the federated service in that other country would have only the needed access. I don’t think this is groundbreaking technologically.
[1]: https://www.reuters.com/article/us-twitter-cyber-netherlands...