On the other hand, America has perfected the science of attracting talents through sophisticated marketing, and providing high paying employment to those who come to America. The US government is pushing to remove PhD students from limits placed on green cards to international students.
Not really. America and many western democratic countries have provided an environment where scientists are respected and cherished for their talent and knowledge not whether they support the regime or not or idolize the country's leader or not. You can curse at Biden and call him an asshole all you want all day long but if you've got the talent and skill, you will be respected and cherished in America. It's that simple. Would you be able to do that in countries like China or North Korea? No. That's the difference and that's not something that they need to market because it's the truth. One day if China allows people to curse at its supreme leader and not allow CCP directives to dictate scientists' ideas and research, trust me all of the talents will flock to China.
It's very difficult as an immigrant to decide what to do, stay in the country that provides incredible opportunities, or return home where family, friends and culture are source of comfort but work opportunities and salaries are more limited.
It's not. All they need to do is ask themselves where they feel is more like home to them. If they feel they can call their adopted country their home, then they will naturally want to stay in their adopted country. If they feel their native country is more like home to them, then they would want to go back to their native country. No country is perfect but what matters is which country is more perfect for the person.