Well never know the true motivation of people who immigrate, but the type of visa can give a lot of insight (school, work, family).
As someone who immigrated to the US and can give my 2 cents - it’s opportunity. Instead of staying in my home country struggling for a job, I can come to the US which is the heart of the industry and has a ton of high paying jobs working a big problems that matter.
And as for US people not immigrating because of their old parents and healthcare, the US does have socialized medicine for the elderly.
As someone who immigrated to the US and can give my 2 cents - it’s opportunity. Instead of staying in my home country struggling for a job, I can come to the US which is the heart of the industry and has a ton of high paying jobs working a big problems that matter.
And as for US people not immigrating because of their old parents and healthcare, the US does have socialized medicine for the elderly.