In your opinion, which of the following options would be better and why?:
3) expand birthright citizenship to other nations so that it becomes a global standard. In this scenario, migrants throughout the world would be granted citizenship wherever they are born, regardless of parental citizenship status.
Among the options that you listed, I'd go with #3.
Because America would no longer be a free country without some of the other protections that are enshrined in the Fourteenth Amendment. Tampering with the Fourteenth Amendment is just too risky.
Also because I am in favor of immigration.
However, I really don't care if other nations adopt this right. I only care about preserving it in America.
I'm for migration because I see it as part of liberty. I believe that if individuals should be socially-economically responsible enough to fully contribute to their own welfare wherever they go, and then why shouldn't people be free to migrate, learn new languages, and travel the world sustainably?
When I ask myself whether that is the direction the world is going in, however, the answer doesn't seem to be yes. The world is mostly dominated by corporations that secure wealth/welfare for distribution within their corporate network by competing against other corporations for resources/money. This includes the welfare state governments of the world, who also strive to make money globally, secure/provide welfare benefits for their system's beneficiaries (their citizens), and seek to exclude non-citizens from joining.
So in that context, what is birthPLACE citizenship except a challenge for other states/corporations to gain access to US labor markets? If you send your people to the US to have babies now, for example, in 20 years or so you can send the adult child to the US to make money and remit it to their 'home country.'
Now, if everyone in the world was free to travel, work, take care of themselves WITHOUT social-political pressure to remit money outside the US by people who want to exploit the 'rich Americans,' then I would say people should be free to migrate through the US as they would be everywhere else.
But when you look at a world where border police check your bank statements before giving you a visa and restrict your ability to work and make money wherever you go, then you should realize that the game is to prevent people from making money by taking 'your citizens' jobs' while sending them abroad to make money and bring it back home. It's basically modern colonialism.