If you are applying for a job that requires no brains, don't put stuff in your resume that gives the impression that you do have brains. Tailor your resume and the job application to the job you are seeking.
A "one size fits all" resume is worthless.
If he thinks he is being rejected for a job for which he is over qualified, then omit some stuff from the resume.
If you are applying for a job working a jackhammer, you don't try to convince your potential employer that you know how to design a better one. The employer is looking for a jackhammer operator, not a jackhammer designer.
BTW, if he has several degrees, does he have any job experience? A lot of kids these days have made it all the way through college without ever flipping a burger or washing dishes or waiting on tables or stocking a shelf or working as a landscaper. I did all those things while I was in school.
That is a lesson a lot of people have trouble learning.
When I applied to be a haunt monster at my local theme park, I did say I had a current job, but I gave no other information about my skills at the job. After all, I’m not trying to run their theme park, or re-design their computer system, I just want to scare guests.
So I want them to think of me has a mindless but conscientious employee who will show up for work, do what I am told, obey instructions, and not make waves.
They certainly didn’t need to know my class ranking for my engineering degree, or that they were going to pay me less a day than I’d make in an hour at my real job.