Why is it so hard to find a job now? Enter Ghost Jobs

I have to put out a ghost job req and interview every person applying within reason for every green card a direct report is applying for. I have to show there are or aren’t any residents or citizens that can fill the job

The main problem is: even if the interviewee knocks it out of the park, is an amazing engineer, I still am not interested in firing my OPT/h1b team member who can still legally work for 2-3 years. So while I will deny their green card application and not submit it, I also won’t hire the interviewee

So when interviewing, perhaps I should skip more places that say citizenship required on the req, to avoid wasting my time?

No. Many (especially smaller) companies don't want to hire people who need visa sponsorship because it requires a decent amount of overhead. The company needs to have an immigration lawyer to prepare and submit paperwork, which many smaller companies don't want to bother with.

FWIW it's illegal to require "US citizenship" in a job description. You can, however, say "eligible to work in the US". (The former would be discriminatory against non-citizen permanent residents). Although I'm also not a lawyer.

There are actually situations where U.S. citizenship can be a requirement, e.g., cleared jobs but there needs to be a really good reason like not being able to obtain clearances.

SpaceX has been through the wringer on this one, so just copy & paste from their listing:

To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.