> Sponsored green cards take like 1.5+ years to process, so someone could be OPT the whole time but the employer would have to get the application rolling quickly after hiring or else risk their employee having to go back to their home country for some period of time when OPT runs out and the green card is approved.
Add to that:
1. Some (many?) companies do not file for green cards right away, because they like to keep their employees tied down with an H1-B. I think my employer has a policy of not applying for a green card until the employee has 5 years or service or something.
2. IIRC, there are country-based quotas for employment-based green cards, so it could take very much longer than 1.5 years to get one. E.g. I think it can take 10+ years for an Indian to get one. Though I think having an active application for one is enough to stay in country for H1-B holders (though I'm even less sure about OPT holders).
Did some policy change in the last 10 years to cause the wait times to go up? Because I just checked the USCIS backlog, and it looks like they're now processing Indian green card applications from 12 years ago, and I've known people who've gotten employment-based green cards in approximately that amount of time.
https://www.uscis.gov/green-card/green-card-processes-and-pr...
I did scan some Cato institute blog post that claimed the wait is 134 years, but they're a biased advocacy organization (so have reason to exaggerate for political effect) and what they say conflicts with what I've personally seen.