Your friend learn practically everything, while the Judo
teachers have only focused on Judo only or a couple of other
martial arts.
Comparing someone who knows Judo only and someone who knows almost
everything, of course those know Judo only will seem sub
standard.
Each and every martial arts has their strengths and weaknesses.
Judo strengths are that trainees learn to fall safely, learn how to
make use of people's CG and their CG to their advantage and get out
of a sticky situation.
If you are able to apply their strengths, Judo is a good martial
art to learn. If you aren't, like your friend says, they are no
better than the juniors in Korea, even if you have a red belt.
