There's no THE greatest country; every country can be great.
US&A has been the escape hatch for oppressive regime in China/Russia/... for many years, young people from there seek freedom in US, instead of fight for freedom in their own.
Individual freedom is great but collectively they made people who can't migrate have less and less freedom. Some expected US&A compensate that with trade, military and twitter, which all turned out to be disasters.
I'm sorry for anyone stuck in those processes, but for long term US&A giving up on Green card / dual citizenship is not necessarily a bad thing for the world.
> Individual freedom is great but collectively they made people who can't migrate have less and less freedom
Damned if we don’t allow people in and, apparently, damned also if we do allow some in
Your strange argument would actually support this policy: stop letting these people into the USA so that they stay in their own repressive countries and are forced to reform them.