I really don't think Big Tech is using H1-B and greencards to buy fake loyalty or cheaper labor. If your current employer applied for a visa for you, your future employer will too. (To some extent, startups get screwed here, since nobody on an H1-B is going to ditch Apple to work at your startup.) H1-B salaries are public information; and they are exactly the same as what everyone else puts on levels.fyi. I worked at Google; I saw the mandatory H1-B job postings and there was no difference in comp or requirements between my role and the ones being advertised. Filling out paperwork so that every qualified candidate in the world can work there is the cost of doing business; if there were more qualified applicants, they'd hire more people. To the visaholders, this is just another perk for working at a big tech company.

When I clicked the link, I thought this article was going to be something like "non-US citizens get an extra $10k in perks because these companies do all their visa work for them, and US citizens don't need a visa". But it's something much more obscure that doesn't matter.