He should consider a graduate degree. With these kind of grades (and as an American citizen), he would easily be able to get a masters or PhD for free, with an additional monthly stipend, from an excellent school.
Yes, grad school at this time seems to be the best option. Hopefully the jobs picture will be clearer in two years when he has his Master’s. During that time, he can network and continue his job search. The MS degree will help him to stand out and shouldn’t add much to his loan debt as he can defer his undergrad loans and get a TA job to pay for Master’s studies.
Join the Air Force. Had a friend do the same thing back in the 90’s and qualified for flight school. It was a 2 year wait so they sent him to grad school and he did contract oversight on military aircraft projects at boeing